Digital Health Technology Applications in Home Care for Children With Complex Medical Conditions: A Scoping Review.

The barbell back squat (BBS) is used widely in strength and conditioning training programs for its functional nature, which allows the overloading of many muscles in a single exercise []. Many muscle groups contribute to the execution of stable and controlled movement during the BBS. The muscles in the legs that have featured most frequently in previous studies of the BBS exercise are the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus, gastrocnemius and gluteus maximus []. Variations in posture and technique are likely to result in alterations in muscle activation. Higher loading has been shown to result in greater muscle hypertrophy compared to lower loading, as long as thresholds for failure are not reached []. There are little data to support the choices of squat parameters by powerlifters and athletes. Athletes can adopt two bar positions on the back during the BBS, the first where the bar sits atop the trapezius muscles, in a high bar position, or lower on the back, at least 3 cm from the top of the anterior deltoids, in a low bar position []. The biomechanical effects of low bar BBS compared to high bar BBS has been estimated through musculoskeletal modelling, the results showed that a high bar barbell position generated a greater muscle activity in the quadriceps muscles, whereas the erector spinae, hip adductors and gluteal muscles had greater muscle activation generated during the low bar BBS []. The effect stance width has on the activation of the leg muscles during the BBS exercise has also been investigated []. In wide stance squats athletes had their feet positioned at twice their hip width. In narrow stance squats athletes had their feet at approximately one and a quarter times their hip width. It was found that there was a higher activation of the gluteus maximus when using a wide stance compared to a narrow stance, and a higher activation in the rectus femoris, vastus lateralis, and vastus medialis for higher weights compared to lower weights []. Similarly, a second study investigated stance width across 70 lifters performing squats at 70% of their one repetition maximum (1RM) []. It was found that narrow stance squats increased the forces on the quadriceps muscles and wide stance increased force in the gluteus maximus, biceps femoris, and semitendinosus [].