Hip posterolateral musculature strengthening in sedentary women with patellofemoral pain syndrome: a randomized controlled clinical trial with 1-year follow-up.

STUDY DESIGN: Randomized controlled trial. OBJECTIVES: To determine if adding hip-strengthening exercises to a conventional knee exercise program produces better long-term outcomes than conventional knee exercises alone in women with patellofemoral pain syndrome (PFPS). BACKGROUND: Recent studies have shown that a hip-strengthening program reduces pain and improves function in individuals with PFPS. However, there are no clinical trials evaluating long-term outcomes of this type of program compared to conventional knee-strengthening and -stretching exercises. METHODS: Fifty-four sedentary women between 20 and 40 years of age, with a diagnosis of unilateral PFPS, were randomly assigned knee exercise (KE) or knee and hip exercise (KHE). The women in the KE group (n = 26; mean age, 23 years) performed a 4-week conventional knee-stretching and -strengthening program. The women in the KHE group (n = 28; mean age, 22 years) performed the same exercises as those in the KE group, as well as strengthening exercises for the hip abductors, lateral rotators, and extensors. An 11-point numeric pain rating scale, the Lower Extremity Functional Scale, the Anterior Knee Pain Scale, and a single-hop test were used as outcome measures at baseline (pretreatment) and 3, 6, and 12 months posttreatment. RESULTS: At baseline, demographic, pain, and functional assessment data were similar between groups. Those in the KHE group had a higher level of function and less pain at 3, 6, and 12 months compared to baseline (P<.05). In contrast, the KE group had reduced pain only at the 3- and 6-month follow-ups (P<.05), without any changes in Lower Extremity Functional Scale, Anterior Knee Pain Scale, or hop testing (P>.05) through the course of the study. Compared to the KE group, the KHE group had less pain and better function at 3, 6, and 12 months posttreatment (P<.05). For the Lower Extremity Functional Scale, the between-group difference in change scores from baseline at 3, 6, and 12 months posttreatment favored the KHE group by 22.0, 22.0, and 20.8 points, respectively. CONCLUSION: Knee-stretching and -strengthening exercises supplemented by hip posterolateral musculature-strengthening exercises were more effective than knee exercises alone in improving long-term function and reducing pain in sedentary women with PFPS.

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. RESULTS: The 3 groups were homogeneous prior to treatment in respect to demographic, pain, and functional scales data. Both the knee exercise and the knee and hip exercise groups showed significant improvement in the LEFS, the AKPS, and the NPRS, when compared to the control group (P<.05 and P<.001, respectively). But, when we considered minimal clinically important differences, only the knee and hip exercise group demonstrated mean improvements in AKPS and pain scores that were large enough to be clinically meaningful. For the single-limb single hop test, both groups receiving an intervention showed greater improvement than the control group, but there was no difference between the 2 interventions (P>.05). 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. LEVEL OF EVIDENCE: Therapy, level 1b-.