Lower Limb Muscle Activation and Ground Reaction Forces During Forward Drop Lunges From Varying Heights

This study investigated lower limb muscle activation and vertical ground reaction forces (GRF) during forward drop lunges from 3 different heights (0, 10, and 20 cm). Twenty-three active male athletes (mean age 21 [2] y; height 178 [6] cm; body mass 70 [9] kg; body mass index 21 [4]) participated. Surface electromyography was recorded from the biceps femoris, vastus lateralis, rectus femoris, and vastus medialis muscles. After maximum voluntary contraction assessment, participants performed drop lunges onto a force platform. Electromyography signals were filtered and normalized to maximum voluntary contraction using MATLAB. Repeated-measures analysis of variance and paired t-tests evaluated the effects of height and side. During the eccentric phase, significant differences emerged in biceps femoris and rectus femoris activation depending on height (P < .05). In the concentric phase, all muscles except left vastus medialis showed significant differences (P < .05). Concentric activation and left-side muscle activity were significantly higher than eccentric and right-side activity, respectively. GRF values increased significantly with drop height (P < .05). However, only concentric phase muscle activation showed a linear relationship with height. These findings suggest that manipulating platform height in lunge training can effectively increase quadriceps activation and GRF without external load, especially in the concentric phase, and may enhance lower-limb strength and performance.