Investigation of the functional stability limits while squatting

Sugama, Atsushi; Tonoike, Yasuhiro; Seo, Akihiko

doi:10.1002/hfm.20833

Cited by 5 publications

(3 citation statements)

References 46 publications

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“…Squat, which is a mixed or a suspensory strategy, is reportedly related to falls (Sugama et al, 2020) and balance ability (Kasahara et al, 2015). However, the intrinsic role of each lower limb joint during squats remains unclear.…”

Section: Introductionmentioning

confidence: 99%

Relationship among the COM Motion, the Lower Extremity and the Trunk during the Squat

Kasahara,

Ishida,

Linjing

et al. 2024

Journal of Human Kinetics

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Squatting is a common motion in activities of daily living and is frequently used in training programs. Squatting requires a shift of the body in both vertical and anterior-posterior directions. Postural control during squatting is considered a mixed strategy; however, details and roles of the trunk and lower limb joints are unclear. The purpose of this study was to investigate the relationship among the kinematics of the lower limb, the trunk and the center of mass (COM) descent during squatting. Twenty-six healthy young adults performed repeated parallel squats. Lower limb joint and trunk angles and the COM were analyzed using a 3D motion analysis system. We evaluated the relationship between the kinematics and the squat depth by performing correlation analysis and multiple linear regression analysis. The ankle was the first to reach its maximum angle, and the remaining joints reached their maximum angles at the maximum squat depth. The knee joint motion and the squat depth were significantly correlated and there was a correlation between the hip and the ankle joint motion and the anteroposterior displacement of the COM during squatting. Multivariate linear regression analysis indicated that squat depth was predicted by both the knee and ankle motion and that anteroposterior displacement of the COM was predicted by the hip, ankle, and knee joint motion. The knees contributed to the vertical COM motion during squatting, while the hips contributed to the COM motion in the anteroposterior direction. On the other hand, the ankles contributed to COM motions in both the vertical and anteroposterior directions during squatting.

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Section: Introductionmentioning

confidence: 99%

Relationship among the COM Motion, the Lower Extremity and the Trunk during the Squat

Kasahara,

Ishida,

Linjing

et al. 2024

Journal of Human Kinetics

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“…In addition to the ankle and hip strategies, the suspensory strategy is the third postural strategy which employs flexing of the knee joints to lower the COM toward the base of support and achieve COM vertical control (3,4). However, this suspensory strategy contributes to balance control by lowering COM, which remains a controversial topic (4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies also suggested that elderly people might be more inclined to use the suspensory strategy, such as bending the knees or lowering the COM to increase posterior stability (3,4). However, a study has reported that different depths of squatting (i.e., different knee flexion angles) decrease the functional stability limits by inducing changes in joint mobility and muscle activation patterns (6). These divergent findings may be partially attributed to variations in the employed resources, such as COM, joint angle, and muscle activation, and assessment method.…”

Section: Introductionmentioning

confidence: 99%

Change in sensory integration and regularity of postural sway with the suspensory strategy during static standing balance

Jiang,

Kasahara,

Ishida

et al. 2023

Front. Neurol.

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Background and aimThe suspensory strategy, a method for controlling postural balance in the vertical direction of the center of mass (COM), is considered by the elderly as a means of balance control. The vertical COM control might alter the sensory integration and regularity of postural sway, which in turn impacts balance. However, to date, this was not confirmed. Thus, this study aimed at investigating the influence of the suspensory strategy achieved through knee flexion on the static standing balance.MethodsNineteen participants were monitored at knee flexion angles of 0°, 15°, and 65°. Time-frequency analysis and sample entropy were employed to analyze the COM data. Time-frequency analysis was utilized to assess the energy content across various frequency bands and corresponding percentage of energy within each frequency band. The outcomes of time-frequency are hypothesized to reflect the balance-related sensory input and sensory weights. Sample entropy was applied to evaluate the regularity of the COM displacement patterns.ResultsKnee flexion led to a decreased COM height. The highest energy content was observed at 65° knee flexion, in contrast with the lowest energy observed at 0° in both the anterior–posterior (AP) and medial-lateral (ML) directions. Additionally, the ultra-low-frequency band was more pronounced at 65° than that at 0° or 15° in the ML direction. Furthermore, the COM amplitudes were notably higher at 65° than those at 0° and 15° in the AP and ML directions, respectively. The sample entropy values were lower at 65° and 15° than those at 0° in the ML direction, with the lowest value observed at 65° in the vertical direction.ConclusionThe suspensory strategy could enhance the sensory input and cause sensory reweighting, culminating in a more regular balance control. Such suspensory strategy-induced postural control modifications may potentially provide balance benefits for people with declining balance-related sensory, central processing, and musculoskeletal system functions.

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Effects of bath chairs on the behavior, muscle workload, and experience in independent bathing of the elderly: A Chinese case study

Liu

Zhang

et al. 2023

International Journal of Industrial Ergonomics

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Investigation of the functional stability limits while squatting

Cited by 5 publications

References 46 publications

Relationship among the COM Motion, the Lower Extremity and the Trunk during the Squat

Relationship among the COM Motion, the Lower Extremity and the Trunk during the Squat

Change in sensory integration and regularity of postural sway with the suspensory strategy during static standing balance

Effects of bath chairs on the behavior, muscle workload, and experience in independent bathing of the elderly: A Chinese case study

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