Effects of impairment-based exercise on performance of specific self-reported functional tasks in individuals with knee osteoarthritis.

BACKGROUND

Little is known regarding how impairment-based exercises may improve performance of specific functional tasks in people with knee osteoarthritis (OA).

OBJECTIVE

The purpose of this study was to compare the probability that participation in an impairment-based exercise program or the same impairment-based program supplemented with agility and perturbation training will improve patient-reported function on specific functional tasks.

DESIGN

This study was a secondary analysis of data from a randomized clinical trial.

SETTING

The study was conducted in the outpatient physical therapy clinic of a large, university-based health center.

PARTICIPANTS

One hundred eighty-three people with knee OA (122 women, 61 men) participated.

INTERVENTIONS

Participants were randomly assigned to either a group that received agility and perturbation training with standard exercise therapy or a group that received only the standard exercise.

MEASUREMENTS

Specific functional items were taken from the physical function subscale of the Western Ontario and McMasters Universities Osteoarthritis Index, the Lower Extremity Function Scale, and the Activities of Daily Living Scale of the Knee Outcome Survey.

RESULTS

The probability of self-reported improvement in a variety of specific functional tasks was low following participation in either of the exercise programs. When only participants with moderate to severe difficulty performing specific functional tasks were considered in the analysis, the probability of success improved but was still limited.

LIMITATIONS

The results are generalizable only to self-reported assessment of performance of specific functional tasks.

CONCLUSIONS

Impairment-based exercise may not be enough to make substantial improvement in performance of specific functional tasks. Task-specific exercise approaches need to be explored for people with knee OA.