Short-Term Effects of Hip Abductors and Lateral Rotators Strengthening in Females With Patellofemoral Pain Syndrome: A Randomized Controlled Clinical Trial

STUDY DESIGN Randomized clinical trial OBJECTIVE To investigate the influence of strengthening the hip abductor and lateral rotator musculature on pain and function of females with patellofemoral pain syndrome (PFPS) BACKGROUND Hip muscle weakness in women athletes has been the focus of many recent studies and is suggested as an important impairment to address in the conservative treatment of women with PFPS However it is still not well established if strengthening these muscles is associated with clinical improvement in pain and function in sedentary females with PFPS METHODS Seventy females (average +/- SD age 25 07 years) with a diagnosis of unilateral PFPS were distributed randomly into 3 groups 22 females in the knee exercise group who received a conventional treatment that emphasized stretching and strengthening of the knee musculature 23 females in the knee and hip exercise group who performed exercises to strengthen the hip abductors and external rotators in addition to the same exercises performed by those in the knee exercise group and of the 25 females who did not receive any treatment The females of the nontreatment group (control) were instructed to maintain their normal daily activities An 11 point numerical pain rating scale (NPRS) was used to assess pain during stair ascent and descent The lower extremity functional scale (LEFS) and the anterior knee pain scale (AKPS) were used to assess function The single limb single hop test was also used as a functional outcome to measure preintervention and 4 week postintervention function CONCLUSION Rehabilitation programs focusing on knee strengthening exercises and knee strengthening exercises supplemented by hip strengthening exercises were both effective in improving function and reducing pain in sedentary women with PFPS Improvements of pain and function were greater for the group that performed the hip strengthening exercises but the difference was significant only for pain rating while descending stairs