Effect of Hip and Core Muscle Strengthening for Patellofemoral Osteoarthritis: A Feasibility Study

The investigators propose to develop and test the feasibility of a 6-week supervised hip and
core muscle exercise intervention for persons with painful patellofemoral osteoarthritis
(PFOA), a common condition for middle-aged and older adults. Currently there is limited
evidence regarding effective conservative interventions for PFOA, a chronic condition that is
painful and limits function and quality of life. Exercise is recommended as a first-line
treatment for knee osteoarthritis, but the optimal type of exercise for PFOA is unknown. This
intervention is based upon similar programs shown to improve pain and function in younger
persons with patellofemoral pain, a condition that may lead to PFOA. Feasibility outcomes
include adherence to the treatment program, recruitment, retention, and the impact of the
intervention on participants' pain and function at 6-weeks and 6 months after finishing the
program. The investigators will also compare PFOA participants to a matched pain-free
volunteer control group to explore the differences in their biomechanics, muscle strength,
pain report, and function at baseline. Data from this feasibility study will be used to
design a future randomized controlled trial investigating the efficacy of conservative
exercise interventions for PFOA. The investigators' overarching goal is to develop a
conservative exercise intervention that improves the symptoms, function, and quality of life
of persons with PFOA.

Inclusion Criteria:

Patellofemoral Osteoarthritis group: 1) age 35-70 years, 2) have been diagnosed with knee
osteoarthritis in one or both knees with symptoms primarily in the anterior knee, 3)
radiographic evidence of ≥ Grade 1 osteophytes or joint space narrowing at the
patellofemoral joint according to the Osteoarthritis Research Society International (OARSI)
grading scale (0 = none, 1 = mild/possible, 2 = moderate/definite, 3 = severe), 4) pain
produced by ≥ 2 of the following: descending steps, ascending steps, sit-to-stand,
squatting, kneeling, prolonged knee flexion, increased activity (e.g., hiking), morning
stiffness < 30 minutes, stiffness after sitting ≥ 30 minutes, history of patellar
subluxation or dislocation in the past.

Control group: 1) age 35-70 years, 2) no known diagnosis by a physician of knee
osteoarthritis, 3) pain free in the lower extremities at the time of enrollment into the
study and for 1 week prior to enrollment.

Exclusion Criteria:

Patellofemoral Osteoarthritis (PFOA) group: 1) the presence of other conditions that may
cause knee pain (e.g., patellar tendonitis, rheumatoid arthritis), 2) neurologic or
musculoskeletal conditions that may alter lower extremity kinematics (e.g., multiple
sclerosis, hip arthritis/arthroplasty), 3) history of a fracture of the knee, 4) pregnancy,
5) knee injections within the past 3 months, 6) inability to understand English.

Control group: 1) all previously listed exclusion criteria for the PFOA group, 2) knee pain
produced by 2 or more of the following: descending steps, ascending steps, sit-to-stand,
squatting, kneeling, prolonged knee flexion, or a history of patellar subluxation or
dislocation in the past.