Femoroacetabular Impingement: Morphology Does Not Equal Pathology

Femoroacetabular Impingement Syndrome (FAIS) was described as early as 19361 and has been drastically increasing in popularity over the past two decades2. As this condition has become more respected amongst the medical community, the number of patients identified with FAIS was significantly increased3. With this increased recognition, there has also been a markedly rising number of hip arthroscopy surgeries being performed. Literature has demonstrated an 18-fold increase from 1999 to 20094 and a 25-fold increase between 2006 and 20135. With regards to indication for surgery, Peters and colleagues performed a scoping review to identify what factors surgeons use to make this decision6. This study found the below criteria used by surgeons for surgical intervention in the literature…

Criteria Studies reporting criteria
Alpha angle > 60°, CE angle > 40°, or presence of acetabular retroversion 72 (67%)
No clinical evidence of inflammatory arthritis changes 69 (64%)
Diagnostric injection or MRI indicating presence of intra-articular pathology or labral damage 66 (61%)
Acetabular retroversion (Crossover sign) 62 (57%)
Failed non-surgical treatment 47 (44%)
Anterior Impingement Test 39 (36%)
Positive FADDIR or Anterior Impingement Test 38 (35%)
Hip pain > 3 months 26 (24%)
Failed formal Physical Therapy-led program 19 (18%)
Lateral centre edge angle > 20° 18 (17%)
Flexion and IR decreased 12 (11%)
CE angle > 40° 8 (7%)
IR decreased 7 (6%)
Hip IR < 20° in 90° hip flexion 6 (6%)
Alpha angle > 60° 2 (2%)

As you can see from the data obtained from their study, the vast majority of the information used to determine surgery in this patient population is related to radiological findings and extent of morphological changes. Most surprisingly, failure of conservative management and especially failure of formal physical therapy was not included in the vast majority of published studies.

With this information, it appears we may be getting ahead of ourselves…

What is FAIS?

The femoroacetabular joint refers to the articulation between the proximal femur and the acetabulum of the pelvis. In FAIS, altered boney morphology of the femoral neck (Cam Morphology) or of the Acetabular rim (Pincer Morphology) leads to premature contact of the two osseous structures. Based on the orientation of the joint, this premature contact typically occurs during hip flexion and/or internal rotation7,8. This abnormal contact has also been blamed for additional pathological conditions such as acetabular labral tears, chondral lesions, and osteoarthritis.

Altered Morphology Does Not ALWAYS Matter

As with most morphological abnormalities, these factors do not always lead to pain and are fairly common in the general and athletic populations. A systematic review conducted by Frank and colleagues9 of 2,114 asymptomatic hips found a very high prevalence of altered morphology. They found that 67% of subjects had radiologically confirmed pincer morphology, whereas 37-55% of athletes and 23% of the general population demonstrated cam morphology. To further evaluate the association of morphology in symptomatic patients, athletes, and asymptomatic individuals, Mascarenhas and colleagues performed a systematic review of 60 studies10. This study found that cam morphology was significantly more common in athletes versus asymptomatic subjects but not compared to symptomatic patients, significantly more common in symptomatic versus asymptomatic cases. Whereas, no significant differences were found between pincer morphology prevalence when comparing athletes to symptomatic patients. However, mixed-type FAI was significantly more common in athletes versus asymptomatic subjects and in asymptomatic versus symptomatic subjects.

Additionally, when looking at those pathologies that are said to be caused by altered morphology, the prevalence is also very high among asymptomatic individuals. The presence of acetabular labral tears and chondral lesions were found in asymptomatic individuals with a prevalence of 44-69% and 20-24%, respectively11,12.

In fact, the level of morphological abnormality often does not coincide with severity of symptoms. A study of 616 adults with hip pain found no association between radiographic signs of FAIS or a positive Flexion Adduction Internal Rotation (FADDIR) test with degree of hip pain13. More recently, Jacobs and colleagues investigated the relationship of preoperative symptom severity and magnitude of boney morphology14. This study of 64 patients prior to arthroscopic hip surgery found no correlation between symptom severity and degree of acetabular labral tear or femoroacetabular boney morphology. There was however a significant influence of depressive symptoms (as determined by the Mental Component Score) and severity of hip-related symptoms, which gives further credence to the link between psychosocial factors and symptom severity irregardless of morphological or pathological changes.

When Does Altered Morphology Matter?

Previous diagnostic criteria for femoroacetabular impingement relied heavily upon the level of morphological changes. Ganz et al. and Sankar et al. determined that the diagnosis of FAIS was appropriate if (1) there was abnormal morphology of the femur and/or acetabulum, (2) if there was abnormal contact between these two structures, (3) if the patient participated in activities that resulted in supraphysiologic motion that results in such abnormal contact and collision, (4) repetitive motion resulting in the continuous insult, (5) presence of soft-tissue damage15,16. Once again, these criteria are not sufficient to accurately diagnose a patient with FAIS because there is no weight put on clinical signs or symptoms.

More recently, Griffin and colleagues attempted to better define appropriate terminology, diagnosis, treatment, and prognosis for FAIS17. At this consensus meeting, they agreed that accurate diagnosis depended upon clinical signs, symptoms, and diagnostic criteria. They therefore defined FAIS as:

“Femoroacetabular impingement syndrome is a motion-related clinical disorder of the hip with a triad of symptoms, clinical signs and imaging findings. It represents symptomatic premature contact between the proximal femur and the acetabulum.”

— 2016 Warwick Agreement on Femoroacetabular Impingement Syndrome (Griffin et al., 2016)

The key differentiating factors between this and previous descriptions are the additional criteria of ‘symptomatic’ and the emphasis on symptoms and clinical signs in addition to diagnostic criteria. This definition was met with a 9.8/10 agreement and allows for the entire patient presentation to be taken into consideration, not just the underlying morphological changes. To expand upon this agreement, Reiman and colleagues performed an international and multi-disciplinary Delphi survey to identify pertinent aspects of the subjective history, clinical examination, and radiological examination18. This survey found agreement on the following aspects in patients presenting with FAIS…

Subjective Examination
Descriptor Consensus Support
Deep anterior groin pain, especially worse with activities such as prolonged sitting, squatting, car transfers, and dressing 98.4%
Pain with hip flexion or rotational activities 96.7%
Pinching or aching in the hip/groin associated with activitity 96.7%
Deep groin pain with twisting or turning or pivoting 95.1%
Intermittent sharp deep groin pain 95.1%

Subjective self report should be the cornerstone of the examination of any injury and FAIS is no exception. Patients often present with reports of deep anterior groin pain that is exacerbated with activities involving deep flexion, rotational activities, and squatting. The subjective attributes agreed upon for individuals presenting with FAIS closely coincides with a diagnostic study performed by Clohisy and colleagues19 who looked at 51 patients with confirmed, symptomatic FAIS. This study showed that 88% of patients had pain localized to the groin region and aggravating factors included general activity-related (71%), running (69%), sitting (65%), and pivoting (63%).

Physical Examination
Descriptor Consensus Support
Limited IR with hip flexion with pain 96.7%
Limited IR with pain 91.8%
Limited and painful hip flexion 83.6%
Special Testing
Descriptor Consensus Support
Positive FADDIR/Anterior Impingement Test 91.8%
No special tests are diagnostic of FAIS; Only valuable as screening tool 82.0%

A systematic review of 16 studies related to physical impairments in individuals with FAIS demonstrates similar findings as the Delphi survey. This study agreed that the available literature currently demonstrates that individuals with FAIS have decreased hip ROM into impingement (flexion/internal rotation in 90° flexion), which is often limited by pain20.

When looking at the included criteria for special testing in FAIS, the two agreed upon findings seem contradictory. On one end, a positive FADDIR test is beneficial, however on the other end, it is also noted that no special tests are diagnostic for FAIS. According to the literature in reference to special testing for FAIS, there has been no test that can be seen as confirmatory of the diagnosis due to very low positive likelihood ratios and specificity values21-23. That being said, the use of the FADDIR test does offer benefit due to the very high sensitivity and low negative likelihood ratios reported in the literature (Sn= 0.94-0.99, -LR= 0.14-0.45)22, however its capacity as a screening method has recently come into question24. A cross-sectional study of 74 ice hockey players (average age of 16 years old) contradicted the current literature with regards to the FADDIR test’s screening capacity. This unique study questions its capacity to screen for pure cam, pincer, or combined morphology (Sn= 0.41, -LR= 1.24) and pure cam or combined morphology (Sn= 0.60, -LR= 0.78). As we continue to evaluate the capacity to screen for FAIS, there will be more consensus, but as of now the FADDIR can be used as a screening tool with caution and with taking into consideration the patient’s additional clinical signs and subjective complaints.

Understanding that FAIS is far more than morphological changes to the proximal femur or acetabulum will allow us as clinicians and researchers to move forward in the evaluation, treatment, and return to sport of this patient population. By evaluating the ability of conservative management to return athletes to their prior level of function, this drastic spike in surgical procedures may start to stabilize. Boney morphology is a well-known contributor to FAIS, but it only tells one portion of the story, we need to dig deeper in order to successfully manage this patient population.

References:

1. Smith-Petersen M. Treatment of malum coxae senilis, old slipped upper femoral epiphysis, intrapelvic protrusion of the acetabulum, and coxa plana by means of acetabuloplasty. J Bone Joint Surg Am. 1936; 18: 869–80.
2. Khan M, Oduwole KO, Razdan P, et al. Sources and quality of literature addressing femoroacetabular impingement: a scoping review 2011-2015. Curr Rev Musculoskelet Med. 2016. doi:10.1007/s12178-016-9364-5.
3. Montgomery SR, Ngo SS, Hobson T, et al. Trends and demographics in hip arthroscopy in the United States. Arthroscopy. 2013; 29: 661–5.
4. Colvin AC, Harrast J, Harner C. Trends in hip arthroscopy. J Bone Joint Surg Am. 2012; 94: e23. dos:10.2106/JBJS.J.01886
5. Cvetanovich GL, Chalmers PN, Levy DM, et al. Hip arthroscopy surgical volume trends and 30-day postoperative complications. Arthroscopy. 2016; 32: 1286–92.
6. Peters S, Laing A, Emerson C, et al. Surgical criteria for femoroacetabular impingement syndrome: a scoping review. British Journal of Sports Medicine. February 2017. doi:10.1136/bjsports-2016-096936.
7. Fernquest S, Arnold C, Palmer A, et al. Osseous impingement occurs early in flexion in cam-type femoroacetabular impingement: a 4D CT model. The Bone & Joint Journal. 2017;99-B(4 Supple B):41-48. doi:10.1302/0301-620X.99B4.BJJ-2016-1274.R1.
8. Kobayashi N, Inaba Y, Kubota S, et al. The Distribution of Impingement Region in Cam-Type Femoroacetabular Impingement and Borderline Dysplasia of the Hip With or Without Cam Deformity: A Computer Simulation Study. Arthroscopy. November 2016. doi:10.1016/j.arthro.2016.08.018.
9. Frank JM, et al. Prevalence of Femoroacetabular Impingement Imaging Findings in Asymptomatic Volunteers: A Systematic Review. Arthroscopy. 2015 Jun;31(6):1199-204. doi: 10.1016/j.arthro.2014.11.042.
10. Mascarenhas VV, Rego P, Dantas P, et al. Imaging prevalence of femoroacetabular impingement in symptomatic patients, athletes, and asymptomatic individuals: A systematic review. European Journal of Radiology. 2016;85(1):73-95. doi:10.1016/j.ejrad.2015.10.016.
11. Register B, et al. Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study. Am J Sports Med. 2012 Dec;40(12):2720-4. doi: 10.1177/0363546512462124.
12. Tresch F, Dietrich TJ, Pfirrmann CWA, Sutter R. Hip MRI: Prevalence of articular cartilage defects and labral tears in asymptomatic volunteers. A comparison with a matched population of patients with femoroacetabular impingement. J Magn Reson Imaging. December 2016:1-12. doi:10.1002/jmri.25565.
13. Yamauchi R, Inoue R, Chiba D, et al. Association of clinical and radiographic signs of femoroacetabular impingement in the general population. J Orthop Sci. November 2016. doi:10.1016/j.jos.2016.09.014.
14. Jacobs CA, Burnham JM, Jochimsen KN, Molina D, Hamilton DA, Duncan ST. Preoperative Symptoms in Femoroacetabular Impingement Patients Are More Related to Mental Health Scores Than the Severity of Labral Tear or Magnitude of Bony Deformity. The Journal of Arthroplasty. July 2017. doi:10.1016/j.arth.2017.06.053.
15. Ganz R, Parvizi J, Beck M, et al. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res 2003; 417: 112–20.
16. Sankar WN, Nevitt M, Parvizi J, et al. Femoroacetabular impingement: defining the condition and its role in the pathophysiology of osteoarthritis. J Am Acad Ortho Surg. 2013; 21(Suppl 1) :S7–S15.
17. Griffin DR, Dickenson EJ, O’Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement. British Journal of Sports Medicine. 2016; 50(19): 1169-1176. doi:10.1136/bjsports-2016-096743.
18. Reiman MP, Thorborg K, Covington K, Cook CE, Holmich P. Important clinical descriptors to include in the examination and assessment of patients with femoroacetabular impingement syndrome: an international and multi-disciplinary Delphi survey. Knee Surg Sports Traumatol Arthrosc. 2017;22(4):806. doi:10.1007/s00167-017-4484-z.
19. Clohisy JC, Knaus ER, Hunt DM, Lesher JM, Harris-Hayes M, Prather H. Clinical Presentation of Patients with Symptomatic Anterior Hip Impingement. Clinical Orthopaedics and Related Research. 2009;467(3):638-644. doi:10.1007/s11999-008-0680-y.
20. Diamond LE, Dobson FL, Bennell KL, Wrigley TV, Hodges PW, Hinman RS. Physical impairments and activity limitations in people with femoroacetabular impingement: a systematic review. British Journal of Sports Medicine. 2015;49(4):230-242. doi:10.1136/bjsports-2013-093340.
21. Pacheco-Carrillo A, Medina-Porqueres I. Physical examination tests for the diagnosis of femoroacetabular impingement. A systematic review. Phys Ther Sport. 2016;21:87-93. doi:10.1016/j.ptsp.2016.01.002.
22. Reiman MP, Goode AP, Cook CE, Holmich P, Thorborg K. Diagnostic accuracy of clinical tests for the diagnosis of hip femoroacetabular impingement/labral tear: a systematic review with meta-analysis. British Journal of Sports Medicine. 2015;49(12):811-811. doi:10.1136/bjsports-2014-094302.
23. Reiman MP, Goode AP, Hegedus EJ, Cook CE, Wright AA. Diagnostic accuracy of clinical tests of the hip: a systematic review with meta-analysis. British Journal of Sports Medicine. 2013;47(14):893-902. doi:10.1136/bjsports-2012-091035.
24. Casartelli NC, Brunner R, Maffiuletti NA, et al. The FADIR test accuracy for screening cam and pincer morphology in youth ice hockey players. J Sci Med Sport. June 2017. doi:10.1016/j.jsams.2017.06.011.

The Athlete’s Hip: Simplifying Evaluation, Treatment, and Return to Sport

The Athlete’s Hip can be a complicated issue for sports medicine professionals and athletes alike… Do you want to learn how to accurately and efficiently evaluate and treat this population?

Currently scheduling for 2018/19, see below for information regarding the course and learn if you want to host a course!

Description:

Hip pathology is an often under-appreciated and misunderstood problem for clinicians and athletes alike. As intra-articular and extra-articular hip pain has become more prominent, surgical procedures have increased exponentially, but examination and conservative management have unfortunately lagged behind.

This two-day course will delve into evidence-based evaluation, conservative management, and return to sport of athletes presenting with hip pain. Through lecture and lab sessions, you will learn how to evaluate and treat athletes presenting with intra-articular (femoroacetabular impingement syndrome, acetabular labral pathology, and ligamentum teres pathology) and extra-articular pathology (sacroiliac joint, extra-articular impingement, athletic pubalgia, piriformis syndrome, proximal hamstring pathology, and greater trochanteric pain syndrome).

By simplifying the evaluation and management of these conditions, at the conclusion of this course, clinician will be more confident in determining underlying pathology, appropriate management, need for surgical consult, and safe return to sport.

Presenter:

John Snyder, PT, DPT, OCS, CSCS

Objectives:

Upon completion of this course, participants will be able to:

  • Understand the complexity of pain and its impact on hip pathology
  • Understand the impact of femoroacetabular biomechanics on hip and concomitant LE pathology and injury risk
  • Be able to accurately assess for red flags (avascular necrosis, femoral stress fracture, and inguinal hernia) and referral from proximal regions
  • Be able to accurately and efficiently evaluate extra-articular and intra-articular hip pathology
  • Be able to screen for and determine the need for surgical intervention
  • Understand pathology dependent and region dependent manual therapy and exercise progression for hip pathology
  • Progression of LE exercise and end-stage rehabilitation principles
  • Be able to determine psychosocial, functional testing, and pathology specific factors to determine safe and efficient return to sport

Schedule

Day 1

09:00 – 09:30 Introduction & Pain Science
09:30 – 10:15 Impact of hip pathology and biomechanics on movement
10:15 – 11:00 Screening of Pelvic/Hip Region (Lab/Lecture)
11:00 – 11:15 Break
11:15 – 12:15 Examination of Intra-articular Pathology (Lecture)
12:30 – 13:30 Lunch
13:30 – 14:30 Examination of Intra-articular Pathology (Lab)
14:30 – 15:15 Examination of Extra-articular Pathology (Lecture)
15:15 – 15:30 Break
15:30 – 16:00 Examination of Extra-articular Pathology (Lab)
16:00 – 17:00 Where does surgery fit in?

Day 2

09:00 – 10:00 Epidemiology of Conservative and Surgical Interventions
10:00 – 10:45 Treatment of Intra-articular hip pathology (Lab/Lecture)
10:45 – 11:00 Break
11:00 – 12:00 Treatment of Extra-articular hip pathology (Lab/Lecture)
12:00 – 13:00 Lunch
13:00 – 14:00 End-stage Rehabilitation Considerations
14:00 – 15:30 Return to Sport Determination (Lecture/Lab)
15:30 – 15:45 Final Comments/Conclusion

Scheduled Dates

I am currently scheduling for 2018-2019. Please contact me if you are interested in hosting The Athlete’s Hip or Management of the Ice Hockey Athlete at your facility.

Lateral Hip Pain? Time to Stop Blaming the Poor Bursa…

Lateral hip pain is a very common occurrence amongst the general population and even more-so for middle-aged women, who demonstrate a 4x higher prevalence then men. In fact, literature has found that 23.5% of women over the age of 50 indicate having persistent lateral hip pain (15% unilateral and 8.5% bilateral)1.

Pain in this region can be caused by various anatomical and neurovascular structures, from the sacroiliac joint to referral from the lumbar spine. However, among these potential structures, the greater trochanteric bursa has historically been to blame2,3 and is likely the most common source…

Or is it?

The beginning of the end for Trochanteric Bursitis started with a study conducted by Bird and colleagues in 20014. With the hypothesis that gluteus medius tendinopathy was the prevailing underlying pathology in lateral hip pain, they evaluated 24 patients via magnetic resonance imaging. The results very much fell in line with their hypothesis as 45.8% had a gluteus medius tear, 62.5% had gluteus medius tendinopathy, and only 8.3% presented with trochanteric bursal distension.

A 2007 study conducted by Silva and colleagues5 set out to further understand whether this persistent lateral hip pain can actually be blamed on an inflamed trochanteric bursa. This prospective, case-controlled, blinded study attempted to determine the histopathologic features of patients with greater trochanteric bursitis versus asymptomatic control subjects. Bursal specimens were obtained following each subject undergoing total hip arthroplasty on the involved hip. Two different blinded surgical pathologists evaluated the samples and found no signs of acute or chronic inflammation in the control or greater trochanteric bursitis groups. Unfortunately, this study had a few significant limitations. One being that it was an extremely small sample size (6 subjects) and the other being that all subjects were undergoing a THA on the involved hip.

Similar to the original article in 2007, Board and colleagues also compared pathohistolgical composition of the trochanteric bursa in individuals undergoing ipsilateral THA. However, this study was performed on a much larger scale with 100 subjects included (50 with greater trochanteric pain and 50 without pain in this region). Once again, this study found no evidence of acute or chronic inflammation in the 100 included subjects, however 20% of subjects in the ‘trochanteric bursitis’ group demonstrated thinning of the gluteus medius tendon6.

This led the authors to conclude…

It is perhaps best to view any involvement of the trochanteric bursae within Greater Trochanteric Pain Syndrome as a secondary event with the inciting initial pathology stemming from either involvement of the ilio-tibial band or from the ‘abductor cuff’ of the hip that is the gluteus medius and minimus tendons — Board et al., 2014

And to continue beating a dead horse, another study demonstrated more confirmatory findings. Long and colleagues7 more recently published a much larger study trying to answer the same question. This retrospective review of musculoskeletal sonographic findings of 877 patients with greater trochanteric pain demonstrated very similar results. Of the included subjects, 700 (79.8%) did not have trochanteric bursitis on ultrasound. The most commonly involved pathological conditions were gluteal tendinosis (438; 49.9%) and a thickened iliotibial band (250; 28.5%).

What’s in a name?

Lateral hip pain… Trochanteric Bursitis… Greater Trochanteric Pain Syndrome (GTPS).

Why does it matter what we call pain localized to the greater trochanteric region? When we think “-itis”, understandably we jump to the conclusion that this an inflammatory disorder and more specifically an inflammatory condition of the bursa in the case of trochanteric bursitis. This then leads to interventions that act to decrease inflammation of the involved structures. These conservative interventions likely start at NSAIDs and end at cortisone injections prior to the eventual progression to surgical interventions. When we look at the interventions studied in the case of GTPS, there is an overwhelming predominance of anti-inflammatory procedures. A systematic review of conservative treatment for GTPS included 8 studies (696 patients). Of these 8 studies, 6 investigated cortisone injections, 2 on extracorpal shockwave therapy, 1 on orthotics, and 1 on ‘home training’8.

That is right, there has yet to be a study looking at activity modification or physical therapy in the treatment of greater trochanteric pain syndrome (however there are two large studies currently underway). And the one study looking at ‘home training’ left A LOT to be desired. This lack of understanding related to the underlying pathology in GTPS has led to an over-reliance on anti-inflammatory interventions in the literature and in clinical practice.

Now that we have all but eliminated trochanteric bursitis from contention, maybe we can finally determine the best way to treat this complex condition…

References:

1. Segal NA, Felson DT, Torner JC, et al. Greater trochanteric pain syndrome: epidemiology and associated factors. Arch Phys Med Rehabil. 2007; 88(8): 988-992. doi:10.1016/j.apmr.2007.04.014.
2. Stegemann H. Die chirurgische Bedeutung paraartikularer Kalka-blagerungen. Arch Klin Chir. 1923; 125: 718-738.
3. Ege Rasmussen KJ, Fano N. Trochanteric bursitis: treatment by corticosteroid injection. Scand J Rheumatol. 1985;14:417–420.
4. Bird PA, Oakley SP, Shnier R, Kirkham BW. Prospective evaluation of magnetic resonance imaging and physical examination findings in patients with greater trochanteric pain syndrome. Arthritis & Rheumatism. 2001;44(9):2138-2145. doi:10.1002/1529-0131(200109)44:9<2138::AID-ART367>3.0.CO;2-M.
5. Silva F, Adams T, Feinstein J, Arroyo RA. Trochanteric bursitis: refuting the myth of inflammation. J Clin Rheumatol. 2008; 14(2): 82-86. doi:10.1097/RHU.0b013e31816b4471.
6. Board TN, Hughes SJ, Freemont AJ. Trochanteric bursitis: the last great misnomer. Hip Int. 2014; 24(6): 610-615. doi:10.5301/hipint.5000154.
7. Long SS, Surrey DE, Nazarian LN. Sonography of Greater Trochanteric Pain Syndrome and the Rarity of Primary Bursitis. American Journal of Roentgenology. 2013; 201(5): 1083-1086. doi:10.2214/AJR.12.10038.
8. Barratt PA, Brookes N, Newson A. Conservative treatments for greater trochanteric pain syndrome: a systematic review. British Journal of Sports Medicine. 2016. doi:10.1136/bjsports-2015-095858.

Femoral Stress Fractures: Identification and Management

The following is an article written for the online, video-based physical therapy continuing education company MedBridge

Stress fractures are a common occurrence amongst the military, cross country, and endurance athlete population patient populations. With the prospective studies indicating an incidence of 31% in military personnel and 21% in track and field athletes, this is an area that needs to be thoroughly understood by clinicians working in a direct access environment. While femoral stress fractures only account for 5-7% of all stress fractures, there is currently no validated clinical decision rule in identifying those at risk and therefore other factors need to be considered by the clinician. (Weishaar et al., 2005; Bennell et al., 1996; Milgrom et al., 1985; Matheson et al., 1987; Monteleone et al., 1995; Changstrom et al., 2014)

What causes a femoral stress fractures?

Stress-related bone and soft-tissue injuries occur in response to an excessive progression of repetitive loading activities. These injuries develop when the extent of the micro-damage exceeds the ability of the remodeling process to keep up with the demands placed upon it. With regards to femoral stress fractures, during running, the largest bending moments about the anterior to posterior axes of the proximal femur occurs during the impact phase of loading response. As this occurs, the largest stress is then placed on the medial aspect of the femur (Edwards et al., 2008)

Who is at risk? (Wright et al., 2015; Bennell et al., 1999)

  • Stress fracture injury rates are highest in girls cross country (10.6), girls gymnastics (7.4), and boys cross country (5.4)
  • In endurance athletes, female sex (odds ratio = 2.31) and previous history of stress fracture (OR = 4.99) were found to be significant risk factors
  • The presence of concomitant ipsilateral Femoroacetabular impingement demonstrates a higher incidence in both the general and military population (Goldin et al., 2015; Carey et al., 2013)
  • Recent, sudden increase in training volume, especially in relatively inactive individuals

What is the clinical presentation? (Clement et al., 1993; Weishaar et al., 2005; Wright et al., 2015)

  • Vague pain in the thigh that radiates into the hip and/or groin region
  • Anterior thigh (45.9%), hip (27.0%), and/or groin (8.1%) pain
  • In femoral shaft stress fractures, hip A/PROM not typically limited, but can be painful, however in femoral neck stress fractures, a gross limitation in A/PROM can be present
  • Groin pain with single leg hop (70%)

Special Testing? (Reiman et al., 2012; Reiman et al., 2015)

1. Patellar-pubic Percussion Test

Reliability Sensitivity Specificity +LR -LR
0.89 0.89 – 0.96 0.82 – 0.95 5.1 – 20.4 0.06 – 0.75

2. Fulcrum Test

Reliability Sensitivity Specificity +LR -LR
N/A 1.00 1.00 0.00

 

Is conservative management effective?

There have been several case reports and case series detailing successful diagnosis, treatment, and return to sport following conservative management. Unfortunately, at this time, there have been no high level studies supporting the physical therapy intervention in this population. In those case studies detailing successful management, programs included progressive posterolateral hip strengthening, neuromuscular re-education, and a graded return to running/physical activity (Weishaar et al., 2005; Ivkovic et al., 2006; Kang et al., 2005).

Without the clinical decision rules for identification of fracture that are available for the foot/ankle (Ottawa Ankle Rules), knee (Ottawa Knee Rules, Pittsburgh Knee Rules), and cervical spine (Canadian Cervical Spine Rules), evaluation of potential hip fracture needs to be managed with the best available evidence. By taking into consideration patient demographics, subjective report of training volume/progression, and utilizing tests/measures supported in the literature, the treating clinician can more accurately identify those athletes in need of further radiological evaluation.

References:

  1. Reiman et al. Diagnostic accuracy of clinical tests of the hip: a systematic review with meta-analysis. Br J Sports Med. 2012
  2. Reiman MP, Mather RC, Cook CE. Physical examination tests for hip dysfunction and injury. British Journal of Sports Medicine. 2015;49(6):357-361. doi:10.1136/bjsports-2012-091929.
  3. Weishaar M. Identification and Management of 2 Femoral Shaft Stress Injuries. Journal of Orthopaedic & Sports Physical Therapy. 2005;35(10):665-673.
  4. Ivkovic A. Stress fractures of the femoral shaft in athletes: a new treatment algorithm. British Journal of Sports Medicine. 2006;40(6):518-520. doi:10.1136/bjsm.2005.023655.
  5. Kang L. Stress fractures of the femoral shaft in women’s college lacrosse: a report of seven cases and a review of the literature. British Journal of Sports Medicine. 2005;39(12):902-906. doi:10.1136/bjsm.2004.016626.
  6. Wright AA, Taylor JB, Ford KR, Siska L, Smoliga JM. Risk factors associated with lower extremity stress fractures in runners: a systematic review with meta-analysis. British Journal of Sports Medicine. July 2015:bjsports–2015–094828–8. doi:10.1136/bjsports-2015-094828.
  7. Edwards WB, Gillette JC, Thomas JM, Derrick TR. Internal femoral forces and moments during running: Implications for stress fracture development. Clinical Biomechanics. 2008;23(10):1269-1278. doi:10.1016/j.clinbiomech.2008.06.011.
  8. Bennell KL, Matheson G, Meeuwisse W, Brukner P. Risk factors for stress fractures. Sports Med. 1999;28:91-122.
  9. Carey T, Key C, Oliver D, Biega T, Bojescul J. Prevalence of radiographic findings consistent with femoroacetabular impingement in military personnel with femoral neck stress fractures. J Surg Orthop Adv. 2013 Spring; 22(1):54-8.
  10. Goldin M, Anderson CN, Fredericson M, Safran MR, Stevens KJ. Femoral Neck Stress Fractures and Imaging Features of Femoroacetabular Impingement. PM R. 2015 Jun;7(6):584-92. doi: 10.1016/j.pmrj.2014.12.008. Epub 2015 Jan 13.
  11. Weishaar M. Identification and Management of 2 Femoral Shaft Stress Injuries. Journal of Orthopaedic & Sports Physical Therapy. 2005;35(10):665-673.
  12. Bennell KL, Malcolm SA, Thomas SA, et al. Risk factors for stress fractures in track and field athletes. A twelve- month prospective study. Am J Sports Med. 1996;24:810-818.
  13. Milgrom C, Giladi M, Stein M, et al. Stress fractures in military recruits. A prospective study showing an unusu- ally high incidence. J Bone Joint Surg Br. 1985;67:732- 735.
  14. Matheson GO, Clement DB, McKenzie DC, Taunton JE, Lloyd-Smith DR, MacIntyre JG. Stress fractures in athletes. A study of 320 cases. Am J Sports Med. 1987;15:46-58.
  15. Monteleone GP, Jr. Stress fractures in the athlete. Orthop Clin North Am. 1995;26:423-432.
  16. Changstrom BG, Brou L, Khodaee M, Braund C, Comstock RD. Epidemiology of Stress Fracture Injuries Among US High School Athletes, 2005-2006 Through 2012-2013. American Journal of Sports Medicine. 2014;43(1):26-33. doi:10.1177/0363546514562739.

Ice Hockey Injuries: Who Gets Hurt and Why Does it Matter?

Ice hockey is an inherently physical sport and as such creates situations where injury is possible and often likely. With the influence that injuries can have on a team’s success, research has started to focus on our ability to assess injury risk and prevent injuries before they occur. However, these strategies cannot be effectively laid out until we first understand who gets hurt, when they get hurt, and how they get hurt.

Who gets hurt?

According to a prospective cohort study performed by Flik et al., there is a significant disparity in injury incidence depending upon player position in NCAA Division 1 ice hockey. Only 6.2% of injuries were sustained by goaltenders, whereas 32.7% were defensemen and 61.1% were forwards. In agreement with this distribution, Agel et al found 9.6% of injuries effected goaltenders, 40.8% were defensemen, and 48.3% were forwards. This information also correlated with a recent study investigating injury incidence during the World Championship and Olympic tournaments, where goaltenders were once again the least injured followed by defensemen and forwards. However, when evaluating injuries in the National Hockey League (NHL), the only significant difference found was a higher likelihood of defensemen missing gametime due to injury in comparison to forwards. This study also found that a significant predictor of missing at least 5 games due to injury included being a goaltender (odds ratio = 1.68). So, while goaltenders do not get injured as often, their return to play is often more extended in comparison to other players. These numbers are likely not as drastically position dependent due to the disparity of position players on the ice at one time (3 forwards, 2 defensemen, and 1 goaltender), which may account for a significant amount of the variance reported in the literature at the collegiate, international, and professional levels.

When do they get hurt?

Understanding when injuries occur during the course of an individual game and throughout the course of the season allows us to understand when an athlete is at an increased risk of injury. With regards to the collegiate level, 65.5% of injuries occur during games and 35.5% during practice. Additionally, preseason practice rates were more than twice as high as in season injury rates. Two studies looked into the distribution of injuries during game play and found drastically different results. Agel and colleagues found that most injuries occurred in the 2nd and 3rd periods, which is likely due to athlete fatigue and intensity of gameplay increasing as the game progresses. In contrast to this report, amongst NHL regular season injuries, the vast majority occur in the first period (48.1%). Intuitively, as the NHL season progresses, the likelihood of injury also increases. This increase in injury rate is likely due to player fatigue and increased intensity of play as teams are fighting for a playoff spot.

How do they get hurt?

Due to the physical nature of ice hockey, the vast majority of injuries are contact-related, however non-contact injuries tend to make up a higher proportion of practice injuries. According to Agel and colleagues, non-contact injuries make up 9.7% of injuries during games, whereas they make up 32% of injuries during practice. During games, approximately 50% of injuries are due to contact with another player and 39.6% are due to contact with another object (boards, puck, etc.). In agreement with these trends, in the NHL body checking made up 28.6% of injuries, while incidental contact (14.3%), hit by puck (13.5%), contact with environment (9.4%), and other intentional player contact (7.4%) made up the bulk of injuries incurred. Aside from these mechanisms, non-contact injuries made up 14.8% of all injuries and accounted for 11.7% of man games lost due to injury (1,921 games) between 2009 and 2012. This gives good insight into the general cause of injury, but what types of injury are most common amongst ice hockey players?

Over a 16 season timeframe, injures most often sustained during gameplay included internal derangement of the knee (13.5%), concussion (9.0%), acromioclavicular joint injury (8.9%), upper leg contusion (6.2%), and musculotendinous strain of the hip/groin region (4.5%). However, distribution of injuries during practice shows a slightly different distribution. The most common injuries during practice were musculotendinous strain of the hip/groin region (13.1%), internal derangement of the knee (10.1%), ankle ligament sprain (5.5%), concussion (5.3%), and acromioclavicular joint injury (4.4%). Looking further at this data, during games, the highest prevalence of severe injuries was knee internal derangement and the most common mechanism of injury was due to player contact. Of the most common severe injuries reported, musculotendinous injuries of the pelvis/hip was the only pathology (6.2%) that had a non-contact mechanism as the most common cause. In agreement with these findings, amongst NHL players, the most common sites of injury include the head (17%), thigh (14%), knee (13%), and shoulder (12%). Additionally, with regards to man games lost, these regions also comprised the largest impact on their respective teams. Unfortunately, this study did not break the body regions into specific injuries/pathologies.

Given the fairly vague description of the injuries reported in these large epidemiological studies, it is also important to look more in depth to determine which specific injuries are actually reported in the literature. With regards to knee ligamentous injuries, Sikka and colleagues found that between 2006 and 2010, only 47 players sustained an anterior cruciate ligament tear in the NHL, which is significantly lower than most professional contact team sports. These injuries included 3 goaltenders, 8 defensemen, and 36 forwards. Of these 47 injuries, the reported mechanism for all but one injury was contact with another player and/or with the boards. In addition to the primary ACL rupture, 68% of injuries reported a concomitant meniscal or medical collateral ligament injury as well. Looking at the more commonly injured MCL, from 2003-04 to 2010-11, 13 MCL injuries were reported within one collegiate ice hockey program. This resulted in ten different players being injured (12.7%) and an incident rate of 0.44 per 1,000 athlete exposures. Of these injuries, 77% were contact related and an acute non-contact injury was reported in 15% of cases.

Looking at the most common non-contact injury, hip/pelvic pathology has also been investigated in the literature for this population. Over a four year span, 890 hip or groin injuries were reported in the NHL. Of those reported, 10.6% were found to be intra-articular in nature. There was a very small difference between injury occurring during games (44.6%) and during practice (41.4%), but the vast majority occurred during the regular season (71.2%). The most frequent intra-articular hip diagnosis made in this cohort was hip labral tear (69.1%), followed by hip osteoarthritis (13.8%), hip loose body (6.3%), femoroactebular impingement (5.3%), other hip injury (3.1%), and hip chondromalacia (2.12%). With regards to player position, injuries per 1000 player-game appearances were significantly higher in goaltenders compared with all other players.

Why does it matter?

Having a successful team depends on multiple factors, but regardless of coaching or talent, injuries can have a significant impact on a team’s ability to win. Unfortunately, the NHL does not readily provide injury data to the general public, however ManGamesLost.com has provided data supporting the negative impact of injuries on a team’s success. Over the past five seasons, the Stanley Cup champion has been among the top five least injured teams throughout the regular season. Along those same lines, this season’s President’s Trophy (best regular season record) winning Washington Capitals also had the least man games lost due to injury. Additionally, with the exception of the Pittsburgh Penguins, none of the top five most injured teams have had consistent success over the past five years. In fact, two of those included in the top five most injured also had the two of the worst overall records over this timeframe (Columbus Blue Jackets and Edmonton Oilers).

Screen Shot 2016-04-24 at 3.29.05 PM

In addition to the obvious impact on team performance, when a player returns from a significant injury, their productivity and durability has the potential to decline in the seasons following their return to play. The presence of a meniscal injury was associated with a decreased length of career for all positions. Furthermore, for wings and centers, the number of games played decreased in the first full season after ACL injury from 71.2 to 58.2 and in the second full season to 59.29. With regard to offensive production, there was a 31% reduction in goals scored per season, 60% reduction in assists, and 42% reduction in total points compared with an uninjured control group. Only 37.5% of players who were previously selected as All-Stars were able to regain this honor upon their return to play.

Finally, there is also a financial impact as well. According to Donaldson and colleagues, between the 2009-10 and 2011-12 seasons, 50.9% of NHL players missed at least one game, which translated to a total salary cost of $218 million per year.

With the substantial impact on team performance and the associated financial implications, understanding how to identify those at risk and develop programs to lessen the likelihood of injury are paramount to a successful organization. Part 2 of this series will delve into the evidence regarding injury risk assessment and prevention in this population of athletes.

References:

1. Agel J, Dompier T, Dick R, Marshall S. Descriptive Epidemiology of Collegiate Men’s Ice Hockey Injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 Through 2003–2004. Journal of Athletic Training. 2007;42(2):241-248.

2. Flik K. American Collegiate Men’s Ice Hockey: An Analysis of Injuries. American Journal of Sports Medicine. 2005;33(2):183-187. doi:10.1177/0363546504267349.

3. Currier, Nathan. “The Most Injured NHL Teams Since the 2009-2010 Season.” ManGamesLost.com. N.p., 12 Apr. 2016. Web. 22 Apr. 2016.

4. Donaldson L, Li B, Cusimano MD. Economic burden of time lost due to injury in NHL hockey players. Inj Prev. 2014;20(5):347-349. doi:10.1136/injuryprev-2013-041016.

5. Epstein DM, McHugh M, Yorio M, Neri B. Intra-articular Hip Injuries in National Hockey League Players: A Descriptive Epidemiological Study. American Journal of Sports Medicine. 2013;41(2):343-348. doi:10.1177/0363546512467612.

6. Grant JA, Bedi A, Kurz J, Bancroft R, Miller BS. Incidence and Injury Characteristics of Medial Collateral Ligament Injuries in Male Collegiate Ice Hockey Players. Sports Health. 2013;5(3):270-272. doi:10.1177/1941738112473053.

7. McKay CD, Tufts RJ, Shaffer B, Meeuwisse WH. The epidemiology of professional ice hockey injuries: a prospective report of six NHL seasons. British Journal of Sports Medicine. 2014;48(1):57-62. doi:10.1136/bjsports-2013-092860.

8. Sikka R, Kurtenbach C, Steubs JT, Boyd JL, Nelson BJ. Anterior Cruciate Ligament Injuries in Professional Hockey Players. American Journal of Sports Medicine. 2016;44(2):378-383. doi:10.1177/0363546515616802.

9. Tuominen M, Stuart MJ, Aubry M, Kannus P, Parkkari J. Injuries in men’s international ice hockey: a 7-year study of the International Ice Hockey Federation Adult World Championship Tournaments and Olympic Winter Games. British Journal of Sports Medicine. 2015;49(1):30-36. doi:10.1136/bjsports-2014-093688.

Hip Pain: Return to Sport Considerations

Pre-arthritic hip pain is a common occurrence among athletes, especially those competing in ice hockey1 and field-based team sports (soccer, rugby, and football).2 While this area receives less attention than knee or shoulder injuries, current research is beginning to improve diagnosis and treatment of both intra-articular and extra-articular hip pathology. But, what about return to sport?

What the Literature Says

Determining an athlete’s readiness to return to sport is complicated. The decision with regards to hip pathology is even more convoluted due to the lack of evidence. Most literature discusses outcomes following arthroscopic surgery, and only a few studies outline the proposed benefit of conservative management.3

The available literature suggests that surgery for femoroacetabular impingement is beneficial in a symptomatic population, with 87% of patients returning to sport and 82% returning to previous level of competition.4 On the other hand, no randomized controlled studies adequately compare conservative and surgical management.5 Unfortunately, at this point the research tends to relate only to reported patient satisfaction, subjective questionnaires, and self-reported return to sport.6

How Do We Determine Return to Sport?

Unlike ACL reconstruction, hip injury lacks sufficient evidence to support return to sport guidelines. According to the 2016 Consensus Statement on Return to Sport, clinicians should combine information from a biological, psychological, and social standpoint.7 These factors include:

  • Health risk based on the athlete’s specific injury (subjective and objective measures)
  • Activity risk of returning to sport (type of sport, competition level, etc.)
  • Risk tolerance (pressure, fear of re-injury, etc.)

The StAART Framework (pictured below) proposed by Shrier and colleagues sums up this approach.8 It allows the clinician to comprehend and address all areas impacted by an individual’s readiness to return to sport.

MC020-205 Starrt Framework Chart_v03

Functional Testing Considerations

A recent systematic review conducted by Kivlan and colleagues demonstrated that several tests are reliable and valid when determining return to sport after hip injuries:9

  • Single-leg Stance
  • Deep Squat
  • Single-leg Squat
  • Star Excursion Balance Test (SEBT) / Y-Balance Test

These tests have appropriate validity and reliability but no solid cut-points, so findings should be interpreted on a patient-specific basis by considering their limb symmetry index during these tasks. Significant increase in medial–lateral sway and worse anterior–posterior control during a dynamic single-leg squat task in individuals with pre-arthric hip pain supports the use of a single-leg squat assessment.10

The modified star excursion balance test (also known as the Lower Quarter Y-Balance Test)  has been successful in identifying asymmetry and impaired proximal stability in many conditions. Recently, Johansson and colleagues performed the first study to determine the criterion and divergent validity of the SEBT in individuals with femoroacetabular impingement11. They determined that SEBT performance in the posterolateral and posteromedial directions had high to moderate criterion validity in relation to the HAGOS subscales for pain intensity and symptoms. Additionally, the posterolateral direction and ADL function showed high to moderate criterion validity. Finally and most importantly, the SEBT showed adequate divergent validity and could successfully differentiate between healthy individuals and individuals diagnosed with FAI.

Several recent studies have investigated if hop testing is appropriate in this population. Kivlan and colleagues evaluated the difference in hop testing (cross-over reach test, medial triple hop test, lateral triple hop test, and cross-over hop test) between the involved and uninvolved hip in dancers with hip pathology.12 All tests demonstrated excellent reliability (0.89 – 0.96); however, only the medial triple hop test showed significant difference between the two limbs with the non-involved limb achieving 17.8 cm more distance than the involved limb.

More recently, Kivlan and colleagues investigated the hop performance between dancers with clinically diagnosed femoroacetabular impingement and an asymptomatic control group. This study found a significant difference of approximately 50 cm when comparing the performance of the FAI group to the asymptomatic control group during both the medial triple hop test and the lateral triple hop test:13

table-remake

Further supporting the use of hop and dynamic balance activities, findings from another recent study determined that following arthroscopic hip surgery and concomitant rehabilitation, patients demonstrated > 90% limb symmetry index in the performance of a single-leg squat test, single-leg vertical jump, single-leg hop for distance, and single-leg side hop.14 While this information shows that we can achieve a LSI that is often used in return to sport of athletes post-ACL reconstruction, functional testing should be used with caution when translating it to a population of athletes with hip pain.

Continue with Caution

In the absence of definitive return to sport criteria, the clinician must focus on the tissue health (the load the tissue can absorb before injury), individual tissue stresses imposed by the athlete’s chosen sport and competition level, and any pertinent psychosocial factors (fear of re-injury).

Return to sport testing should be considered with caution as little evidence is available for this patient population.

References:

1. Lerebours F, Robertson W, Neri B, Schulz B, Youm T, Limpisvasti O. Prevalence of Cam-Type Morphology in Elite Ice Hockey Players. Am J Sports Med. 2016 Jan 28. pii: 0363546515624671. [Epub ahead of print]

2. Gerhardt MB, Romero AA, Silvers HJ, Harris DJ, Watanabe D, Mandelbaum BR. The Prevalence of Radiographic Hip Abnormalities in Elite Soccer Players. American Journal of Sports Medicine. 2012;40(3):584-588. doi:10.1177/0363546511432711.

3. Wall PD, Fernandez M, Griffin D, Foster N. Nonoperative Treatment for Femoroacetabular Impingement: A Systematic Review of the Literature. PMRJ. March 2013:1-9. doi:10.1016/j.pmrj.2013.02.005.

4. Casartelli NC, Leunig M, Maffiuletti NA, Bizzini M. Return to sport after hip surgery for femoroacetabular impingement: a systematic review. British Journal of Sports Medicine. 2015;49(12):819-824. doi:10.1136/bjsports-2014-094414.

5. Reiman MP, Thorborg K, Hölmich P. Femoroacetabular Impingement Surgery Is on the Rise—But What Is the Next Step? Journal of Orthopaedic & Sports Physical Therapy. 2016;46(6):406-408. doi:10.2519/jospt.2016.0605.

6. Sim Y, Horner NS, de SA D, Simunovic N, Karlsson J, Ayeni OR. Reporting of non-hip score outcomes following femoroacetabular impingement surgery: a systematic review. J Hip Preserv Surg. 2015;2(3):224-241. doi:10.1093/jhps/hnv048.

7. Ardern CL, Glasgow P, Schneiders A, et al. 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern. British Journal of Sports Medicine. May 2016. doi:10.1136/bjsports-2016-096278.

8. Shrier I. Strategic Assessment of Risk and Risk Tolerance (StARRT) framework for return-to-play decision-making. British Journal of Sports Medicine. 2015; 49: 1311–15.

9. Kivlan BR, Martin RL. Functional Performance Testing of the Hip in Athletes: A Systematic Review for Reliability and Validity. International Journal of Sports Physical Therapy. 2012;7(4):402-412.

10. Freke MD, Kemp J, svege I, Risberg MA, Semciw A, Crossley KM. Physical impairments in symptomatic femoroacetabular impingement: a systematic review of the evidence. British Journal of Sports Medicine. June 2016. doi:10.1136/bjsports-2016-096152.

11. Johnansson AC, et al. The Star Excursion Balance Test: Criterion and divergent validity on patients with femoral acetabular impingement. Manual Therapy. 2016; 26(C): 104-109. doi:10.1016/j.math.2016.07.015.

12. Kivlan BR, Carcia CR, Clemente FR, Phelps AL, Martin RL. Reliability and validity of functional performance tests in dancers with hip dysfunction. International Journal of Sports Physical Therapy. 2013 Aug;8(4):360-9.

13. Kivlan BR, et al. Comparison of Range of Motion, Strength, and Hop Test Performance of dancers with and without a Clinical Diagnosis of Femoroacetabular Impingement. International Journal of Sports Physical Therapy. 2016; 11(4): 527-535.

14. Tijssen M, van Cingel R, de Visser E, Sanden der MN-V. A clinical observational study on patient-reported outcomes, hip functional performance and return to sports activities in hip arthroscopy patients. Physical Therapy in Sport. 2016;20(C):45-55. doi:10.1016/j.ptsp.2015.12.004.

Evidence-Based Strength Training: Gluteus Maximus

To build upon my previous post regarding Evidence-based Strength Training of the Gluteus Medius, I wrote the following article for MedBridge Education

Pain and Gluteal Strength

The gluteal musculature has been implicated in many different pathologies due to its potential impact on lower extremity biomechanics. During weight bearing, the femur moves about a fixed patella and therefore excessive femoral internal rotation and adduction results in increased contact directed primarily at the lateral facet of the patella1. Just 10° of IR can lead to a substantial decrease in PFJ contract area and a 50% increase in joint stress. Coinciding with these findings, Souza et al.2 found that females with patellofemoral pain syndrome (PFPS) demonstrated greater peak hip internal rotation compared to the control group during running, drop jump, and step down. The PFPS group also demonstrated 14% weaker hip abductor strength and 17% weaker hip extensor strength. Wilson et al3, Noehren et al4, and Nakagawa et al5 found that individuals presenting with PFPS demonstrated increased hip adduction during running, jumping, and single-leg squats. This excess femoral adduction creates an increased valgus force about the knee joint, which in turn causes increased loading of the lateral patellofemoral joint. In addition to patellofemoral pain, a hip etiology or influence has also been implicated in iliotibial band syndrome6, anterior cruciate ligament rupture7, and achilles tendinopathy8. More specifically, impaired gluteus maximus function has been demonstrated in individuals diagnosed with femoroacetabular impingement9.

Gluteal strengthening and Rehabilitation

In support of a gluteal etiology, several studies have found the effectiveness of gluteal strengthening in the treatment of lower extremity disorders. A recent systematic review conducted by Santos and colleagues9 found gluteal strengthening decreased the highest intensity of pain experienced during the previous week, pain when ascending and descending stairs, and pain while squatting or sitting for prolonged periods amongst individuals diagnosed with PFPS. Additionally, with regards to rehabilitation following anterior cruciate ligament reconstruction, the inclusion of hip strengthening appears to improve sagittal plane dynamic balance at three months post ACLR as compared to traditional rehabilitation10.

EMG Activity and Exercise Goals

According to Reiman et al.11 and Escamilla et al.12, moderate electromyographic activity (EMG) activation (21-40% MVIC) is best used to facilitate endurance and neuromuscular re-education; high activation (41-60+% MVIC) in order to promote strength gains.

From Biomechanics to Exercises

Gluteus Maximus

Origin: Ilium posterior to posterior gluteal line; dorsal surface of sacrum and coccyx; sacrotuberous ligament

Insertion: Iliotibial tract and gluteal tuberosity

Primary Function: Extends thigh and assists in hip abduction and external rotation; steadies thigh and assists in rising from sitting position

Among introductory exercises, the gluteus maximus achieves the highest EMG levels during:

  1. Front-plank with Hip Extension
  2. Gluteal Squeeze
  3. Side-plank with Hip Abduction
  4. Quadruped with Contralateral Arm/Leg Lift
  5. Uni-lateral Bridge

screen-shot-2016-09-19-at-2-51-18-pm

Additionally, you must consider the interaction of other muscles acting with or against the gluteus maximus when determining exercise prescription. It has been proposed that individuals who demonstrate excess femoral internal rotation during functional tasks may be relying too heavily on the tensor fasciae latae to control their pelvis in the presence of weak or inhibited gluteus medius musculature.

Selkowitz and colleagues determined that the following exercises achieved the best Gluteal to Tensor Fasciae Latae Activation Ratio:

  1. Clamshell
  2. Side-step with resistance band
  3. Single-leg bridge
  4. Quadruped hip extension with knee extended
  5. Quadruped hip extension with knee flexed

screen-shot-2016-09-19-at-2-55-12-pm

Finally, when progressing your patient towards more functional closed kinetic chain and sport/activity-specific exercises, the following exercises achieve the highest gluteus medius activation:

  1. Cross-over Step-up
  2. Hip Thrust Variations (Barbell, Band, American)
  3. Rotational Single-Leg Squat
  4. Skater Squat
  5. Single-Leg Squat

screen-shot-2016-09-19-at-2-56-43-pm

Exercise prescription is a multi-faceted decision, which is driven by the individual patient’s goals, functional limitations, and the evidence supporting the treatment of these factors. Using EMG studies to drive the selection of exercise is highly valuable, especially during early stages of rehabilitation or when attempting to isolate individual muscles and/or groups of muscles. However, there are limitations when comparing different studies due to methodological differences (type of EMG, patient population, data analysis, etc.). Additionally, due to the cost and time to conduct these studies, there are thousands of exercises that have not been evaluated in the literature. In light of this information, these studies should be used to guide your decision making, it should not override your clinical expertise when accompanied by biological plausibility.