The Effects of a Forward Lunge with Hip Adduction on Muscle Activity and Plantar Pressure in Healthy Subjects

The Effects of a Forward Lunge with Hip Adduction on Muscle Activity and Plantar Pressure in Healthy Subjects

Background Patellofemoral pain syndrome (PFPS) is one of the most common causes of anterior knee pain seen in adolescents and adults under the age of 60 yr. The same quadriceps exercise as the forward lunge is important in the treatment of PFPS, and the selective strengthening of the vastus medialis oblique muscle (VMO) exercise is also required. Purpose The purpose of this study was to compare whether the forward lunge with hip adduction (ADD) and the forward lunge with hip neutral position (NEU) affected plantar pressure and muscle activity in the VMO and vastus lateralis muscle (VL) in healthy subjects. Study design A cross-sectional study Methods This study included 20 healthy subjects. The plantar pressures were measured with a gait checker, and the VMO and VL muscle activity was measured with a wireless surface elec-tromyography. Results The results showed that there were significant differences in plantar pressure between the conditions in the medial forefoot and lateral rearfoot (p<0.05). However, there were no significant differences between the conditions in the lateral forefoot and the medial rearfoot (p>0.05). The muscle activity of the VMO was significantly different between the conditions (p<0.05), but the muscle activity of the VL was not (p>0.05). Conclusions Although VMO and VL muscle activity increased with hip adduction, there was an excessive pressure change between the medial forefoot and the lateral rearfoot. The change in plantar pressure in the forward lunge with hip adduction can cause valgus stress on the knee joint, which can aggravate anterior knee pain. For healthy subjects, forward lunge with hip neutral position is recommended.