EFFECTS OF HIP CORE MUSCLE STRENGTHENING AND KNEE MUSCLES STRENGTHENING EXERCISES ON PAIN, STRENGTH AND FUNCTIONAL DISABILITY AMONG PATIENTS WITH PATELLOFEMORAL PAIN SYNDROME

Abstract

Background: Patellofemoral Pain Syndrome (PFPS) is a prevalent musculoskeletal disorder characterized by anterior knee pain, impaired muscular strength, and functional limitations. Although both proximal and knee-focused strengthening exercises are commonly incorporated into rehabilitation programs, the comparative effectiveness of hip and core strengthening versus knee strengthening remains clinically relevant.

Objective: To compare the effects of hip and core muscle strengthening exercises with knee muscle strengthening exercises on pain intensity, functional status, and muscle strength among patients with PFPS.

Methodology: A randomized comparative study was conducted among 30 patients aged 20–40 years recruited through purposive sampling from a private clinical setting in Lahore. Participants were randomly allocated into two equal groups. The Hip/Core Strengthening Group (n = 15) received hip and core strengthening exercises, whereas the Knee Strengthening Group (n = 15) received knee strengthening exercises. Both groups additionally received conventional physiotherapy comprising activity modification, postural training, cryotherapy/thermotherapy, transcutaneous electrical nerve stimulation (TENS), and soft-tissue mobilization. Treatment was administered three times per week for 12 weeks. Pain intensity, functional status, and muscle strength were assessed before and after treatment using the Visual Analogue Scale (VAS), Kujala Patellofemoral Questionnaire, and Hand-Held Dynamometry (HHD), respectively. Data were analyzed using SPSS. Paired-samples t-tests, independent-samples t-tests, and the Mann–Whitney U test were applied as appropriate, with statistical significance set at p < 0.05.

Results: Both groups demonstrated statistically significant improvements in pain intensity, functional status, and muscle strength following the intervention (p < 0.001). Mean VAS scores decreased from 6.18 ± 1.16 to 4.13 ± 1.25 in the Hip/Core Strengthening Group and from 5.85 ± 1.00 to 4.41 ± 1.10 in the Knee Strengthening Group. A statistically significant between-group difference was observed for pain intensity (p = 0.010), favoring the Hip/Core Strengthening Group. Kujala scores increased from 55.20 ± 4.43 to 67.87 ± 6.42 in the Hip/Core Strengthening Group and from 55.67 ± 6.06 to 66.60 ± 6.05 in the Knee Strengthening Group; however, the between-group difference was not statistically significant (p = 0.268). HHD-measured muscle strength increased from 21.55 ± 3.01 to 26.50 ± 3.20 in the Hip/Core Strengthening Group and from 22.43 ± 4.10 to 26.51 ± 4.61 in the Knee Strengthening Group, with no statistically significant between-group difference (p = 0.061).

Conclusion: Both hip and core strengthening and knee strengthening exercises, when combined with conventional physiotherapy, significantly improved pain, functional status, and muscle strength in patients with PFPS. However, hip and core strengthening produced a significantly greater reduction in pain intensity, whereas improvements in functional status and muscle strength were comparable between the two groups. Hip and core strengthening may therefore represent a particularly beneficial exercise strategy for reducing pain in individuals with PFPS.