Strengths and limitations
hip muscle, hip abductors
BLIND
The major strengths of our study are that we provided a home-based exercise program for patients with guidance to make sure their proper technique during the exercise. The home-based exercise does not require any gym equipment, which makes the intervention feasible and generalizable for future implementation. Additionally, we used the regularly remote support to provide health education and adjustment of training load to create continuously adequate stimuli of muscle in the process of intervention. Other strengths that ensured the quality of the study include its use of blinded assessments and data analyses, the low participant withdrawal rate, and the high intervention adherence rate. Moreover, the outcome measures were extensive and included both clinical and isokinetic strength testing.This study has several limitations. Due to the nature of the interventions in this study, it was not feasible to blind the participants and therapists involved in home exercise and health education. However, blinding of the assessor and statistician was carried out for the outcome measures. Hip muscle strength was not evaluated in the present study. PFP patients exhibited weaknesses in the hip abductors, which may increase stress in the patellofemoral joint. However, hip muscle strengthening was included in the exercise program due to the lack of a reliable method to evaluate the muscle strength of this muscle group in isokinetic muscle testing. The intervention program consisted of core training and stretching, in addition to quadriceps training, to provide better outcomes for patients with PFP. However, these interventions, especially stretching exercises, may also influence muscle strength. Our intervention lasted only six weeks; thus, the long-term effects of this home-based exercise program on the patients’ outcomes could not be determined. In the home-based exercise program, the intensity is largely based on individual perceived exertion. Consequently, the total physical effort of each exercise was not measured, limiting the program’s comparability to those in other studies.