Influence on the Ground Reaction Force Parameters According to Wearing Positions of Backpacks During Stair Ascending and Descending

Abstract

Purpose : The purpose of this study was to investigate the influence on the ground reaction force parameters according to wearing positions of backpack for during stair ascending and descending.Methods : Participants selected as subject were consisted of young female(n=10) and performed stairs walks(ascending and descending) with 2 types of wearing position(front of trunk [FT], rear of trunk [RT]). Passive(Fz 1) and active(Fz 2) forces of the vertical GRF were determined from time function and frequency domain. Also shear forces(Fx, Fy 1, Fy 2), dynamic postural stability index(MLSI, APSI, VSI, DPSI), loading rate and center of pressure (COPx, COPy, COP area) were calculated from time function and frequency domain.Results : Fx, Fy 1, Fy 2, and Fz 1 in GRF didn't show significant differences statistically according to the wearing positions of backpack(p>.05), but stair descending showed higher forces than that of stair ascending. Particularly, Fz 2 of stair ascending showed higher forces than that of stair descending(p<.001), RT types showed higher than that of FT types(p<.05). MLSI, APSI, VSI, and DPSI of stair descending showed the increased stability index than that of stair ascending(p<.05), MLSI of RT types showed the decreased stability index than that of FT types(p<.05). Loading rate didn't show significant differences statistically according to the wearing positions of backpack(p>.05), but stair descending showed higher loading rate than that of stair ascending(p<.001). Also, COPx in stair descending showed the increased movement than that of stair ascending(p<.05).Conclusions : A backpack of 10 kg(10 kg(ratio of body weights 17.61±1.17%) showed significantly change GRF parameters according to wearing positions during stair ascending and descending. If possible, we suggest that the dynamic stability, in case of stairs walking with a smaller weights can be further improved.

Effect of two different exercises on balance, pain and ankle motor function in male college students with chronic ankle instability

“…Patient with CAI have been reported to experience various sports injuries due to ankle instability during landing, which is an essential movement not only in sports situations but also in daily life [42]. To evaluate ankle instability of patients with CAI, GRF was measured using methods such as the gait test, vertical jump, and drop landing [30,31,43]. In the present study, the COP 95% confidence ellipse area was measured during drop landing and it was confirmed that both PEG and SEG significantly decreased the ellipse area compared to NTG.…”

“…The variable of the GRF generated based on the time when the affected foot landed on the ground during drop landing was presented at a sampling rate of 2000 Hz. The center of pressure (COP) 95% confidence ellipse area was analyzed by determining the square area created during ground contact when the posture was maintained after landing [31]. Three successful landing motions were recorded, and the most stable motion was selected and used for analysis [32].…”

Quantitative Analysis on the Variations of Ground Reaction Force during Ascent and Descent of Bus Stairs in Women

“…The 2nd vertical peak value of active force value is occurred by muscular contraction of near articular system. That is, the 1st vertical value is occurred at 1st touch-down during descending when COG of body transfer to forward-gravity direction, and the 2nd vertical peak value is occurred when COG of body transfer to forward-antigravity direction during ascending (Hyun & Ryew, 2015).…”