Changes in Muscle Activation during Wall Slides and Squat-Machine Exercise

Abstract

Closed kinetic chain exercises are commonly used in strengthening and rehabilitation programs. Altering positions of body segments and supports might affect the way these exercises are performed. The purpose of this study was to compare gluteal, quadriceps, hamstring, and plantar flexor muscle activations during wall-slide (WS) vs. squat-machine (SM) exercise. In addition, the effects of support location and foot position were investigated. Twenty women performed 8 exercises, to 60° of knee flexion. Results indicated that placing the foot forward caused an increase in all muscle activations except in the plantar flexors, which showed an increase with the foot placed in line with the hip. This effect was exaggerated during WS for the plantar flexors and quadriceps and during SM for the hamstrings. When the support was located at the scapular level, hamstring and gluteal activations were greater, and quadriceps activity was less during SM than during WS. These results could be used to target specific muscle groups during strengthening exercise.

Influence of knee alignment on quadriceps cross-sectional area

“…Imbalance between the vastus medialis (VM), which pulls the patella inward, and the vastus lateralis (VL), which pulls the patella outward, may cause patellofemoral pain syndrome (PFPS) (Fredericson and Yoon, 2006;Sakai et al, 2000). Therefore, a number of studies have sought methods to recruit the individual muscles which compose the quadriceps complex (Escamilla et al, 1998;Anderson et al, 1998;Blanpied, 1999;Hung and Gross, 1999;Ninos et al, 1997). Representative methods for strengthening the quadriceps include closed kinetic chain (CKC) exercises, such as the squat and leg press, and open kinetic chain (OKC) exercises, such as leg extension.…”

Muscle Activation during Lower Body Resistance Training

“…Previous studies have evaluated the squat, leg press and knee extension [13], the squat and leg press [14], variations of the squat and the lunge [34], as well as combinations of rehabilitation exercises [3,18,21]. However, a number of studies that assessed the quadriceps muscle group activation during resistance training exercises used low loads, body weight only, the same load for all exercises, or did not normalize the EMG to maximum voluntary isometric contraction (MVIC), thus limiting the significance of these studies or making it difficult to compare the results to other research [3,5,12,21,23,31,34]. At present, no source has evaluated a large number of exercises that incorporate knee extension, for the purpose of comparing activation of the quadriceps and hamstring muscles groups, their activation ratios, and gender differences therein.…”

Modelling the joint torques and loadings during squatting at the Smith machine

“…This limitation is overcome when the back is supported by a wall (wall squat), and by a sliding or lever machine (machine squat). These methods have been subjected to biomechanical analysis by Blanpied (1999) and more recently by Escamilla and co-workers (2009). However, the trunk is constrained so that its inclination during the exercise is fixed (wall squat and slidingmachine squat) or changes only according to equipment mechanical design (lever-machine squat).…”