How to squat? Effects of various stance widths, foot placement angles and level of experience on knee, hip and trunk motion and loading

Abstract

BackgroundSquatting is a core exercise for many purposes. The tissue loading during squatting is crucial for positive adaptation and to avoid injury. This study aimed to evaluate the effect of narrow, hip and wide stance widths, foot position angles (0°, 21°, and 42°), strength exercise experience, and barbell load (0 and 50% body weight, experts only) during squatting.MethodsNovice (N = 21) and experienced (N = 21) squatters performed 9 different variations of squats (3 stance widths, 3 foot placement angles). A 3D motion capture system (100 Hz) and two force plates (2000 Hz) were used to record mediolateral knee displacement (ΔD*), range of motion (RoM) at the hip and knee joints, and joint moments at the hip, knee, and lower back.ResultsBoth stance width and foot placement angles affected the moments at the hip and knee joints in the frontal and sagittal planes. ΔD* varied with stance width, foot placement angles and between the subjects’ level of experience with the squat exercise as follows: increasing foot angle led to an increased foot angle led to an increased ΔD*, while an increased stance width resulted in a decreased ΔD*; novice squatters showed a higher ΔD*, while additional weight triggered a decreased ΔD*.ConclusionsSuitable stance width and foot placement angles should be chosen according to the targeted joint moments. In order to avoid injury, special care should be taken in extreme positions (narrow stand-42° and wide stance-0°) where large knee and hips joint moments were observed.Electronic supplementary materialThe online version of this article (10.1186/s13102-018-0103-7) contains supplementary material, which is available to authorized users.

An analysis of the perceived causes leading to task-failure in resistance-exercises

“…The variability in reporting which of the target muscle groups was the limiting factor in each exercise can partly be explained by technical variation in the way the exercises were performed. For example, different stance widths, foot placement, and forward lean during the squat can affect the moments at the hip and knee joints ( Escamilla et al, 2001 ; Glassbrook et al, 2017 ; Lorenzetti et al, 2018 ). It is interesting to consider whether variations in the perceived muscle group being the limiting factor in a given exercise can lead to different adaptations, such as strength and hypertrophy.…”

The effect of increasing heel height on lower limb symmetry during the back squat in trained and novice lifters

“…Inertial forces were neglected due to slow accelerations of the segments. The focus was placed on the sagittal plane, as this is the primary plane of motion during the squat movement [25,28,50]. A > 0.04 m/s threshold in the vertical velocities of the acromion markers was used to define the start and end points of each single squat cycle [25,50].…”

“…Prior to testing, 77 retro-reflecting markers were attached to the skin adjacent to key anatomical landmarks on the lower limbs, pelvis, trunk and arms [25,50]. Two additional markers were attached to the end of the barbell ( Fig.…”

“…1). Each participant was given a standardised set of instructions [25] that encouraged participants to squat down as "low as possible", with the minimal acceptable depth requiring the upper leg to be at least parallel with the ground. A 2 min rest was provided between sets to minimize possible effects of fatigue [51].…”

“…The back squat is a key element in many athletic strength and conditioning programs [25][26][27][28], and is considered a symmetrical bilateral movement [29]. This has resulted in the back squat (and variations such as single leg squat and overhead squat) being used frequently as clinical tests of lower limb symmetry [18,[30][31][32][33][34][35][36].…”