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Motion and Muscle Analysis in Individuals with Femoroacetabular Impingement: A Pilot Study

IRB Number: 2014-030
not enrolling new patients

February 23, 2010

Institutional Review Board, Hospital for Special Surgery

The safety of our participants is our top priority. The trial/study is approved and periodically reviewed by the Institutional Review Board (IRB), which includes doctors, administrators, ethicists, and members of the general public. The safety of clinical trials is reviewed by the U.S. Food and Drug Administration.

Before enrolling in a clinical trial or research study, the investigator will explain the purpose of the trial/study, its expected benefits, any possible risks or side effects, and what your role will be. If you want to join the trial/study, you must sign informed consent documents. You can leave a trial/study at any time without penalty.

For further information, see Understanding Clinical Trials/Research Studies.

Principal Investigator

Bryan T. Kelly, MD


Anil S. Ranawat, MD
Struan H. Coleman, MD
Howard J. Hillstrom PhD
Sherry I. Backus, PT, DPT, MA
Andrew Kraszewski, MS
Erin Magennis


Documentation of the gait abnormalities and motion limitations seen in individuals with FAI will advance the current understanding of the effect of FAI on function. Identification of the relative contribution of selected hip muscles during walking and functional tasks will ultimately assist in the development of more effective non-surgical treatments and post-operative rehabilitation plans for patients with FAI.

10 individuals with FAI and 10 controls will be enrolled.  Individuals with FAI will be enrolled from the offices of Drs. Ranawat and Kelly.  Control subjects will be solicited from the general population for volunteer participation. Preliminary screening (with the exception of clinical measures) will occur at the time of recruitment either in person or on the phone with the subject. This screening will be done by any of the co-investigators.  Initial evaluation and enrollment of control subjects will be conduced by Drs. Ranawat, Kelly or Maak. Radiology consent will be obtained at the time of initial enrollment.  For control subjects, consent will be obtained at the time of the visit to the Motion Analysis Laboratory by Sherry Backus PT, DPT, MA or Howard Hillstrom PhD.

This will be a cross-sectional study and thus no follow-up will be required for individuals with FAI or controls. Enrollment with conclude when 10 individuals with FAI and 10 controls have been enrolled.

Inclusion/Exclusion Criteria

Inclusion Criteria:

Male subjects aged 18-45 years will be included.

A total of twenty individuals will be enrolled for this study protocol.

Ten male test subjects with a diagnosis of FAI based on all of the following inclusion criteria:

  1. Positive impingement test on clinical examination.
  2. Evidence of exclusively FAI cam-type impingement on plain anteroposterior and lateral plain radiographs
  3. Prior magnetic resonance imaging of the symptomatic hip including: labral and chondral separations from the anterior acetabular rim or tears.11,12
  4. Age: 18-45

Ten male subjects will be enrolled as healthy controls with the following inclusion criteria:

  1. No history of lower extremity or spine surgery
  2. No complaints of back, hip or groin pain or other current lower extremity musculoskeletal or neurological pathology.
  3. Normal anteroposterior pelvis radiograph with no evidence of FAI.
  4. Symmetrical, pain free, hip ROM.
  5. Age: No more than one year older than the oldest individual with FAI and no more than one year younger than the youngest individual with FAI enrolled in this study.
  6. Ambulatory without assisted device.
  7. Age: 18-46

Note: specifics are included in the body of the protocol.

Exclusion Criteria:

  • Prior history of hip surgery, osteoarthritis of the hip
  • Pincer lesions or other radiographic abnormalities
  • Current worker’s compensation claim as this has been previously associated with poor outcomes in femoroacetabular impingement.2
  • Clinical evidence of limb length discrepancy (LLD) greater than 2 cm based on lengths from the anterior superior iliac spine to the medial malleolus as measured with a tape measure.
  • Use of a cane or assistive device for ambulation