The effects of two different arm positions and weight status on select kinematic variables during the bodyweight squat

The bodyweight squat is a common movement and is safe and effective. There are many variations and techniques, but little research has explored alterations of the movement. The purpose of this study was to examine the effects of 2 arm positions on select kinematic variables during the bodyweight squat. The participants were classified as normal-weight (NW: n = 17, height: 1.67 ± 0.06 m, weight: 61.25 ± 6.90 kg, body mass index BMI]: 21.92 ± 1.68) or overweight (OW: n = 11, height: 1.68 ± 0.06 m, weight: 88.91 ± 16.86 kg, BMI: 31.64 ± 6.06) according to BMI. The participants completed a bodyweight squat with the arms held at the sides (AP1) followed by a bodyweight squat with the arms held at shoulder level (AP2). Reflective markers were placed on the shoulder, hip, knee, base of the fifth toe, and heel. Data were recorded and analyzed using Peak 9. Trunk and knee flexion was analyzed using separate repeated measures analyses of variance. Overweight participants exhibited reduced knee (OW: 75.56 ± 17.94°; NW: 83.73 ± 13.03°; p < 0.05) and trunk flexion (OW: -78.18 ± 17.72°; NW: -90.65 ± 17.57°; p = 0.05). Holding the arms at shoulder level resulted in greater knee flexion (AP1: 80.81 ± 15.17°; AP2: 86.31 ± 15.21°; p < 0.01). Both weight status and arm position affected the range of motion in the bodyweight squat. Using an arms-up position should be considered, especially for the OW population, to increase the benefits of the bodyweight squat by increasing the range of motion.