Patellofemoral pain,there are many factors to consider including quadriceps strength and function, foot motion and mobility, muscle flexibility, pain sensitivity, and most importantly load management.
What happen when hip loss strength?
The hip controls half of the patellofemoral joint.Patellofemoral pain is thought to be caused by too much lateral tracking of the knee cap on the thigh.
Importantly, thigh motion is controlled by the hip joint, and research has shown us that greater rolling in motion at the hip leads to greater lateral tracking of the knee cap in people with patellofemoral pain.
Picture Shows of lateral tracking of the patella in people with patellofemoral pain, including rolling in motion of the hip joint.
Pelvis drops on opposite side, eventually placing tension on the lateral aspect of leg and pulling the patella outward
Hip collapses inward and rolls under the patella due to poor function and weakness of the hip musculature.The main is glute medius. Why, read our previous post on Glute medius.
over pronation can lead to valgus of knee joint and dropping of pelvic bone which causing more stress on patella .
Although few clinicians stress on vmo strengthening in patelofemoral pain syndrome, data have shown that only general quads exercises are equally effective.
PFPS improves faster with hip + knee exercise compare to knee exercise alone.
Study suggest that hip adductor strengthening does not have effect on knee but abductor, external rotator and extensors are most effective.
Fukuda et Al reported that only hip+ knee strengthening ex group reported improvement at 12 months follow up compare to group receiving quadriceps strengthening exercises alone.
Clinical bottom line ( What you should implement in your clinical practice)
Current high-quality evidence supports the addition of hip-muscle strengthening to knee-focused strengthening and stretching for individuals with PFPS to help reduce pain and improve function.
Based on the reviewed literature, clinicians should consider exercises for the hip abductors (eg, side-lying and standing hip abduction with TheraBand or ankle weights), external rotators (eg, seated external rotation with TheraBand), and extensor muscles (eg, hip-extension machines) when treating patients with PFPS.
Clinicians should also use knee- focused strengthening exercises and stretching exercises for the hamstrings, iliotibial band, gastrocnemius, and quadriceps.
For the strengthening exercises, 2 to 4 sets of 10 to 15 repetitions should be performed. squats, lunges, quadriceps sets, step-ups, terminal knee extension
The stretching exercises should be held for 30 seconds and performed 3 times consecutively a minimum of 3 times per week for 4 weeks.
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Neal, B., et al., Runners with patellofemoral pain have altered biomechanics which targeted interventions can modify: a systematic review and meta-analysis. Gait Posture, 2016. In Press.
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Willy, R.W., J.P. Scholz, and I.S. Davis, Mirror gait retraining for the treatment of patellofemoral pain in female runners. Clin Biomech (Bristol, Avon), 2012. 27(10): p. 1045-51.
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Lack, S., et al., Proximal muscle rehabilitation is effective for patellofemoral pain: a systematic review with meta-analysis. Br J Sports Med, 2015. 49(21): p. 1365-76.
pic courtesy : Physio-pedia