scholarly journals Influence of the Relative Difference in Chair Seat Height according to Different Lower Thigh Length on Floor Reaction Force and Lower-limb Strength during Sit-to-Stand Movement

2004 ◽  
Vol 23 (6) ◽  
pp. 197-203 ◽  
Author(s):  
Takayoshi Yamada ◽  
Shin-ichi Demura
Keyword(s):  
Lower Limb ◽  
Reaction Force ◽  
Relative Difference ◽  
Seat Height ◽  
Sit To Stand ◽  
Lower Limb Strength ◽  
Floor Reaction Force

Improving sit-to-stand transition by the saddle-assistive device in the spinal cord injury: A case study

2021 ◽  
pp. 095441192110033
Author(s):  
Akbar Hojjati Najafabadi ◽  
Saeid Amini ◽  
Farzam Farahmand
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Lower Limb ◽  
Reaction Force ◽  
Assistive Device ◽  
Limb Weakness ◽  
Sit To Stand ◽  
Lower Limb Weakness ◽  
Wide Range ◽  
Cord Injury

Physical problems caused by fractures, aging, stroke, and accidents can reduce foot power; these, in the long term, can dwindle the muscles of the waist, thighs, and legs. These conditions provide the basis for the invalidism of the harmed people. In this study, a saddle-walker was designed and evaluated to help people suffering from spinal cord injury and patients with lower limb weakness. This S-AD works based on body weight support against the previously report designs. This saddle-walker consisted of a non-powered four-wheel walker helping to walk and a powered mechanism for the sit-to-stand (STS) transfer. A set of experiments were done on the STS in the use of the standard walker and the saddle-assistive device(S-AD). A comparison of the results showed that this device could reduce the vertical ground reaction force (GRF) of the legs up to 70%. Using this device could help a wide range of patients with lower limb weakness and SCI patients in changing from sitting to standing.

The association between anthropometric, lower limb strength, and balance variables with 5-repetition sit-to-stand test performance in physically active elderly women

2020 ◽  
Vol 28 (4) ◽  
pp. 325-331
Author(s):  
Zuzana Kováčiková ◽  
Javad Sarvestan ◽  
Zuzana Gonosova ◽  
Petr Linduska ◽  
Erika Zemkova ◽  
...  
Keyword(s):  
Lower Limb ◽  
Elderly Women ◽  
Balance Control ◽  
Knee Extensor ◽  
Physically Active ◽  
Stand Test ◽  
Sit To Stand ◽  
Knee Extensor Strength ◽  
Lower Limb Strength ◽  
Flexor Strength

BACKGROUND: Sit-to-stand test is very often used as measure of lower limb strength in elderly adults. However, the recent findings indicate that performance in this test is also influenced by other factors. OBJECTIVE: To investigate the association between anthropometric, lower limb strength, and balance variables with the 5-repetition sit-to-stand test (5RSTST) in elderly women. METHODS: Forty physically active elderly women ⩾ 60 years underwent the 5RSTST and anthropometric, balance, and lower limb strength assessment. Anthropometric measurements included height and weight. Balance was quantified in the bipedal upright stance on the basis of the centre of pressure sway in the anteroposterior (CoPAP) and mediolateral (CoPML) direction. Bilateral concentric strength of the ankle plantarflexors and dorsiflexors, knee flexors and extensors, and hip extensors was measured. RESULTS: The time to complete the 5RSTST was significantly but mildly associated with height (r= 0.356, p= 0.024), ankle dorsiflexor strength (r=-0.413, p= 0.017), knee flexor strength (r=-0377, p= 0.030), knee extensor strength (r=-0.411, p= 0.017), hip flexor strength (r=-0.359, p= 0.040) on dominant limb, and balance in both directions (AP, r= 0.651, p< 0.001; ML, r= 0.647, p< 0.001). Balance control in AP direction and knee extensor strength on dominant limb were the only factors that contributed independently to 5RSTST, accounting for 55% of the variance. Balance control in AP direction alone explained 41% of the variance in 5RSTST. CONCLUSIONS: Balance control in AP seems to be the most important factor explaining the 5RSTST performance.

scholarly journals Analysis of Sit-to-Stand Movement by Measuring Floor Reaction Force

1988 ◽  
Vol 3 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Toshihiko YONEDA ◽  
Satoru INOUE ◽  
Hiroyuki KAWAMURA ◽  
Maki KOYANAGI ◽  
Akira KIMURA ◽  
...  
Keyword(s):  
Reaction Force ◽  
Sit To Stand ◽  
Floor Reaction Force

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

scholarly journals COVID-19 era in long-term cardiac rehabilitation programs: how was muscle strenght and lean mass affected in cardiovascular patients?

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
M Borges ◽  
M Lemos Pires ◽  
R Pinto ◽  
G De Sa ◽  
I Ricardo ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cardiac Rehabilitation ◽  
Lean Mass ◽  
Lower Limb ◽  
Lower Limbs ◽  
Phase Iii ◽  
Face To Face ◽  
Home Based ◽  
Lower Limb Strength

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Exercise prescription is one of the main components of phase III Cardiac Rehabilitation (CR) programs due to its documented prognostic benefits. It has been well established that, when added to aerobic training, resistance training (RT) leads to greater improvements in peripheral muscle strength and muscle mass in patients with cardiovascular disease (CVD). With COVID-19, most centre-based CR programs had to be suspended and CR patients had to readjust their RT program to a home-based model where weight training was more difficult to perform. How COVID-19 Era impacted lean mass and muscle strength in trained CVD patients who were attending long-term CR programs has yet to be discussed. Purpose To assess upper and lower limb muscle strength and lean mass in CVD patients who had their centre-based CR program suspended due to COVID-19 and compare it with previous assessments. Methods 87 CVD patients (mean age 62.9 ± 9.1, 82.8% male), before COVID-19, were attending a phase III centre-based CR program 3x/week and were evaluated annually. After 7 months of suspension, 57.5% (n = 50) patients returned to the face-to-face CR program. Despite all constraints caused by COVID-19, body composition and muscle strength of 35 participants (mean age 64.7 ± 7.9, 88.6% male) were assessed. We compared this assessment with previous years and established three assessment time points: M1) one year before COVID-19 (2018); M2) last assessment before COVID-19 (2019); M3) the assessment 7 months after CR program suspension (last trimester of 2020). Upper limbs strength was measured using a JAMAR dynamometer, 30 second chair stand test (number of repetitions – reps) was used to measure lower limbs strength and dual energy x-ray absorptiometry was used to measure upper and lower limbs lean mass. Repeated measures ANOVA were used. Results Intention to treat analysis showed that upper and lower limbs lean mass did not change from M1 to M2 but decreased significantly from M2 to M3 (arms lean mass in M2: 5.68 ± 1.00kg vs M3: 5.52 ± 1.06kg, p = 0.004; legs lean mass in M2: 17.40 ± 2.46kg vs M3: 16.77 ± 2.61kg, p = 0.040). Lower limb strength also decreased significantly from M2 to M3 (M2: 23.31 ± 5.76 reps vs M3: 21.11 ± 5.31 reps, p = 0.014) after remaining stable in the year prior to COVID-19. Upper limb strength improved significantly from M1 to M2 (M1: 39.00 ± 8.64kg vs M2: 40.53 ± 8.77kg, p = 0.034) but did not change significantly from M2 to M3 (M2 vs M3: 41.29 ± 9.13kg, p = 0.517). Conclusion After CR centre-based suspension due to COVID-19, we observed a decrease in upper and lower limbs lean mass and lower limb strength in previously trained CVD patients. These results should emphasize the need to promote all efforts to maintain physical activity and RT through alternative effective home-based CR programs when face-to-face models are not available or possible to be implemented.

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