Muscle Activation and Kinematic Analysis during the Inclined Leg Press Exercise in Young Females

Abstract

Knee joint muscle activation imbalances, especially weakness in the vastus medialis oblique, are related to patellofemoral pain within the female population. The available literature presents the leg press as an exercise which potentially targets vastus medialis oblique activation, thus reducing imbalances in the quadriceps muscles. The main aim of the present study was to compare thigh muscle activation and kinematic parameters under different conditions during the inclined leg press exercise in a young female population. A cross-sectional study was conducted on 10 young, trained females. Muscle activation of the vastus medialis oblique, vastus lateralis, rectus femoris and gluteus medialis was analyzed under five different inclined leg press conditions, modifying the feet rotation (0–45° external rotation) and the stance width (100–150% hip width) on the footplate. All the conditions were performed at two different movement velocities: controlled velocity (2″ eccentric–2″ concentric) and maximal intended velocity. Mean propulsive velocity, maximum velocity and maximum power were also assessed. The results show that both controlled velocity conditions and maximal intended velocity conditions elicited a similar muscle activation pattern with greater activation during the concentric phase (p < 0.001, ηp2 = 0.96). The maximal intended velocity conditions showed greater overall muscle activation (p < 0.001, ηp2 = 0.91). The vastus medialis oblique presented the greatest muscle activation, followed by the rectus femoris, vastus lateralis and, the gluteus medialis. Furthermore, the inclined leg press condition with 0º feet rotation, 100% hip width distance and the maximal intended velocity generated the greatest kinematic parameter outputs. In conclusion, the inclined leg press exercise might be an optimal exercise to target vastus medialis activation regardless of the feet rotation and stance width conditions.

Backseat Inclination Affects the Myoelectric Activation During the Inclined Leg Press Exercise in Recreationally Trained Men

“…The ILP exercise uses muscles with different morphology (monoarticular and biarticular), force production depending on joint positions (moment arm, lengthtension relationship), and whether the muscle acts as a prime mover or stabilizer (2,6,16). For this reason, the manipulation of the ILP and its variations have been analyzed in several studies (1,5,10,11), including the effects of changes in feet position (low and high) (1,5), stance widths (wide and narrow) (5,10,11), and feet angle positions (5,10,11) on myoelectric activity.…”

“…Martin-Fuentes et al (10) analyzed 10 young trained female subjects on myoelectric activity (vastus medialis oblique, vastus lateralis [VL], rectus femoris, and gluteus medius) under different ILP conditions: feet rotation (0° or 45° external rotation), feet stance width (100 or 150% hip width) on the footplate and 2 different movement velocities (maximum intended and 2-sec:2-sec velocities). The authors concluded that the myoelectric activity pattern for the 0°-100%, 45°-100%, and 0°-150% conditions was similar, with no preferential myoelectric activity.…”