The comparison of muscle length and strength of lower extremity in athletes with and without patellofemoral pain syndrome

Aim. Development of patellofemoral pain syndrome is considered multifactorial. Muscle tightness or shortness,and muscle strength is challengeable issue in athlete with patellofemoral pain syndrome. The aim of this study was to investigate the muscle length and strength of lower extremity in athletes with and without patellofemoral pain syndrome. Methods. Thirty female athletes (15 patellofemoral pain, 15 controls) were assessed for hamstring (SLR), quadriceps (ELY), gastrocnemious, soleus muscles length with use of universal goniometer, hip external rotators and abductors strength with use of hand held dynamometer and Visual Analog Scale (VAS) scores for pain. Results. The patellofemoral pain group had significantly lesser hamstring length (P=0.046), hip external rotators (P=0.028) and abductors (P=0.001) strength did the control group. Athletes with patellofemoral pain demonstrated significantly increase length of soleus (P=0.026) and gastrocnemius (P=0.028) muscles compared to control group (P<0.05). Conclusion. This study found that athletes with patellofemoral pain had longer plantarflexors, shorter hamstring, weaker hip external rotators and abductors. It is not obvious whether these are a cause or effect of the condition. We suggested that perhaps gluteus maximus weakness play a part in plantarflexors lengthening and hamstring shortening. Further study is suggested to investigate how muscle length and strength changes with rehabilitation, and the relationship with pain.