Influence of knee extension in sitting position with hip adduction on surface EMG of quadriceps muscles in patients with patellofemoral pain syndrome / 医用生物力学

Objective To investigate the possible effect of fully knee extension in sitting position with or without hip adduction on quadriceps imbalance in patients with patellofemoral pain syndrome (PFPS) by using surface electromyography (sEMG). Methods sEMG signals of vastus lateralis (VL) and vastus medialis oblique (VMO) muscles from 30 patients with PFPS as PFPS group and 30 healthy subjects as control group were collected, during their fully knee extension in sitting position with or without hip adduction. All the EMG data were then analyzed by extracting time domain indexes, namely, the root mean square (RMS) and integrated EMG (IEMG), to compare the balanced relationship between VL and VMO muscles. Results In PFPS group, there were no significant differences in VL time domain indexes during knee extension in sitting position with or without hip adduction, while statistical differences were found in VMO time domain indexes, and values of RMS and IEMG of VMO were higher under hip adduction, which indicated that the VMO muscle recruitment was strengthened. Conclusions Fully knee extension in sitting position with hip adduction can promote EMG activities of VMO muscles in patients with PFPS, which will help to balance the VL and VMO muscles.

Effect of double-leg semi-squats with hip adduction on the vastus medialis oblique of patients with patellofemoral pain syndrome / 中华物理医学与康复杂志

Objective To investigate the possible effect of performing double-leg semi-squats with hip adduction on the imbalance between vastus lateralis (VL) and vastus medialis oblique (VMO) muscles of patients with patellofemoral pain syndrome (PFPS).Methods Thirty patients with PFPS were selected to be in the study group,matched with 30 healthy subjects who were enrolled as the control group.Electromyography was used to record VL and VMO activities while the subjects performed double-leg semi-squats (DSs) and double-leg semi-squats with hip adduction (DSs-HA).Results In the study group,when performing DSs,the average RMS was (103.31 ± 44.54) μV and the IEMG was (8.02 ±3.45) μVs for VL.For VMO the RMS was (85.02 ±41.19) μV and the IEMG was (6.72 ±3.20) μVs.The differences in the time domain indexes (RMS,IEMG) between VL and VMO were both significant during DSs (P ＜ 0.05).There was no significant differences during DSs-HA (P ＞ 0.05).The time domain indexes (RMS,IEMG) of VMO were significantly different in both the DSs and DSs-HA (P ＜ 0.05).Conclusions Stronger sEMG signals were seen from the VMO in the double-leg semi-squats with hip adduction than without hip adduction,which indicates that more selective VMO activation can be obtained in the exercise with hip adduction to help balance the VL and VMO.

Microsurgical Selective Obturator Neurotomy for Spastic Hip Adduction

OBJECTIVE: Cerebral palsy may induce harmful spastic hip adduction. We report the result of microsurgical selective obturator neurotomy, performed on 12 spastic hip adductions of 6 patients, followed clinically for at least 26 months postoperatively. METHODS: Microsurgical selective obturator neurotomies, involving microsurgical resection of the anterior obturator nerve branches were performed on 6 patients from January 2000 through June 2003. All patients presented with the inability to sit and 2 patients complained of persistent, intractable pain. We used intraoperative bipolar stimulation to identify selected motor branches. RESULTS: The procedure was performed bilaterally in all patients. In the 3 patients in whom contractures were present, microsurgical selective obturator neurotomies were accompanied by an additional tenotomy of the adductor muscles. Selective tibial neurotomy was performed on three of six patients who originally presented with a spastic ankle. Postoperatively, all spastic hip adductions were corrected more than 60 degrees in passive abduction-adduction amplitude. However, one patient who did not receive active postoperative physiotherapy demonstrated a decreased passive abduction-adduction amplitude upon follow-up. There were no surgical complications. CONCLUSION: We think microsurgical selective obturator neurotomy may be an effective procedure in the treatment of localized, harmful spastic hip adduction after failure of well conducted conservative treatment. As muscular contractions are often associated with spasticity of the hip adductors, an adjunctive tenotomy may be an option. Comprehensive postoperative physiotherapy is essential to improve long-term results.

GENDER DIFFERENCES OF LOWER EXTREMITY KINEMATICS DURING SINGLE LEG LANDING / 体力科学

The higher anterior cruciate ligament (ACL) injury rate of females is one of the most sever athletic-related problems today. The purpose of this study is to compare the lower extremity kinematics between male and female during single leg landing.Six male and four female healthy subjects participated in this study. They jumped from a 32 cm high box and landed with the dominant leg. The landing action was filmed with three video cameras. The knee flexion, knee valgus/varus, and hip adduction/abduction angle and angle velocity were calculated.In female subjects, the knee flexion angle and hip adduction angle were greater compared to males. Also, the knee valgus velocity and hip adduction velocity were higher in females.Our results suggest that knee valgus kinematics may be related to hip adduction. It is important to evaluate hip kinematics when considering knee kinematics to prevent knee ligament injuries.