scholarly journals The Relationship of Knee-Extensor Strength and Rate of Torque Development to Sit-to-Stand Performance in Older Adults

2013 ◽  
Vol 65 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Katie Crockett ◽  
Kimberly Ardell ◽  
Marlyn Hermanson ◽  
Andrea Penner ◽  
Joel Lanovaz ◽  
...  
Keyword(s):  
Older Adults ◽  
Knee Extensor ◽  
Sit To Stand ◽  
Rate Of Torque Development ◽  
Knee Extensor Strength ◽  
Relationship Of ◽  
The Relationship ◽  
Torque Development

Relationship of The Knee Extensor Strength But Not The Quadriceps Femoris Muscularity With Sprint Performance in Sprinters: A Reexamination and Extension

2021 ◽  
Author(s):  
Miyuki Hori ◽  
Tadashi Suga ◽  
Masafumi Terada ◽  
Takahiro Tanaka ◽  
Yuki Kusagawa ◽  
...  
Keyword(s):  
Knee Extensor ◽  
Knee Extension ◽  
Quadriceps Femoris ◽  
Sprint Performance ◽  
Sprint Time ◽  
Knee Extensor Strength ◽  
Significant Difference ◽  
The Absolute ◽  
Relationship Of ◽  
The Relationship

Abstract Purpose: This study examined the relationships of the knee extensor strength and quadriceps femoris size with sprint performance in sprinters. Methods: Fifty-eight male sprinters and 40 body size-matched male non-sprinters participated in this study. The knee extensor isometric and isokinetic strengths were measured using a dynamometer. The isokinetic strength measurements were performed with slow and fast velocities at 60°/s and 180°/s, respectively. The quadriceps femoris muscle volume (MV) was measured using magnetic resonance imaging. The relative values of the knee extensor strengths and quadriceps femoris MV were normalized to body mass.Results: The absolute and relative values of the two velocity isokinetic strengths, but not of isometric strength, of the knee extension were significantly higher in sprinters than in non-sprinters (both Ps < 0.05). Such a significant difference was also observed for the relative quadriceps femoris MV (P = 0.018). In sprinters, there were significant correlations between all three knee extensor strengths and quadriceps femoris MV (r = 0.421 to 0.531, all Ps £ 0.001). The absolute and relative strengths of the fast-velocity isokinetic knee extension correlated with personal best 100-m sprint time (r = -0.477 and -0.409, respectively, both Ps £ 0.001). By contrast, no significant correlations were observed between absolute and relative quadriceps femoris MVs and personal best 100-m sprint time. Conclusions: These findings suggest that despite the presence of the relationship between muscle strength and size, the knee extensor strength may be related to superior sprint performance in sprinters independently of the quadriceps femoris muscularity.

Reliability and Validity of the Sit-to-Stand as a Muscular Power Measure in Older Adults

2020 ◽  
Vol 28 (3) ◽  
pp. 455-466 ◽  
Author(s):  
Jennifer J. Sherwood ◽  
Cathy Inouye ◽  
Shannon L. Webb ◽  
Jenny O
Keyword(s):  
Older Adults ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Handgrip Strength ◽  
Intraclass Correlation ◽  
Negative Relationship ◽  
Reliability And Validity ◽  
Sit To Stand ◽  
Relationship Of ◽  
The Relationship

The study aims were to analyze the reliability and validity of the GymAware™ linear position transducer’s velocity and power measures during the sit-to-stand, compared with the Dartfish 2D videography analysis, and to assess the relationship of age and handgrip strength with velocity and power in 48 older men and women (77.6 ± 11.1 years). The results showed excellent agreement between GymAware- and Dartfish-derived sit-to-stand velocity (intraclass correlation coefficient2-1 = .94 and power intraclass correlation coefficient2-1 = .98) measures. A moderate and negative relationship was found between age and velocity (r = −.62; p < .001) and age and power (r = −.63; p < .001). A moderate and positive relationship was found between handgrip strength and velocity (r = .43; p = .002) and handgrip strength and power (r = .54; p < .001). The results show the GymAware velocity and power measures during the sit-to-stand in older adults to be reliable and valid.

scholarly journals Hip Abductor and Adductor Rate of Torque Development and Muscle Activation, but Not Muscle Size, Are Associated With Functional Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Marcel Bahia Lanza ◽  
Kelly Rock ◽  
Victoria Marchese ◽  
Odessa Addison ◽  
Vicki L. Gray
Keyword(s):  
Functional Performance ◽  
Muscle Thickness ◽  
Muscle Size ◽  
Rate Of Torque Development ◽  
Hip Abduction ◽  
Hop Test ◽  
Hip Abductor ◽  
Relationship Of ◽  
The Relationship ◽  
Torque Development

Understanding the physiological variables that contribute to a functional task provides important information for trainers and clinicians to improve functional performance. The hip abductors and adductors muscles appear to be important in determining the performance of some functional tasks; however, little is known about the relationship of the hip abductor/adductors muscle strength, activation, and size with functional performance. This study aimed to investigate the relationship of maximum torque, rate of torque development (RTD), rate of activation (RoA), and muscle thickness of the hip abductors [tensor fascia latae (TFL) and gluteus medius (GM)] and adductor magnus muscle with the Four Square Step Test (FSST) and the two-leg hop test in healthy young adults. Twenty participants (five males) attended one testing session that involved ultrasound image acquisition, maximal isometric voluntary contractions (hip abduction and hip adduction) while surface electromyography (EMG) was recorded, and two functional tests (FSST and two-leg side hop test). Bivariate correlations were performed between maximum voluntary torque (MVT), RTD at 50, 100, 200, and 300ms, RoA at 0–50, 0–100, 0–200, and 0–300, and muscle thickness with the dynamic stability tests. For the hip abduction, MVT (r=−0.455, p=0.044) and RTD300 (r=−0.494, p=0.027) was correlated with the FSST. GM RoA50 (r=−0.481, p=0.032) and RoA100 (r=−0.459, p=0.042) were significantly correlated with the two-leg side hop test. For the hip adduction, there was a significant correlation between the FSST and RTD300 (r=−0.500, p=0.025), while the two-leg side hop test was correlated with RTD200 (r=0.446, p=0.049) and RTD300 (r=0.594, p=0.006). Overall, the ability of the hip abductor and adductor muscles to produce torque quickly, GM rapid activation, and hip abductor MVT is important for better performance on the FSST and two-leg hop tests. However, muscle size appears not to influence the same tests.

scholarly journals Efficacy of cardiac rehabilitation with motion assistance from wearable cyborg hybrid assistive limb in patients with chronic heart failure: a randomized controlled trial

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Watanabe ◽  
A Koike ◽  
H Kato ◽  
L Wu ◽  
K Hayashi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Cardiac Rehabilitation ◽  
Exercise Therapy ◽  
Knee Extensor ◽  
Control Group ◽  
Cardiac Events ◽  
Rehabilitation Programs ◽  
Sit To Stand ◽  
Knee Extensor Strength

Abstract Background Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking. Purpose We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure. Methods This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated. Results There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group. Conclusion The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

Respiratory Periodicity and Electroencephalogram Arousals During Sleep in Older Adults

2007 ◽  
Vol 8 (4) ◽  
pp. 249-260 ◽  
Author(s):  
Barbara Waag Carlson ◽  
Virginia J. Neelon ◽  
John R. Carlson ◽  
Marilyn Hartman ◽  
Sunil Dogra
Keyword(s):  
Older Adults ◽  
Exploratory Study ◽  
High Variability ◽  
Arterial Oxygenation ◽  
Type B ◽  
Breathing Patterns ◽  
The Mean ◽  
Relationship Of ◽  
The Relationship ◽  
Electroencephalogram Eeg

The aim of this exploratory study was to examine the relationship of electroencephalogram (EEG) arousals to breathing patterns and the relationship of both arousals and breathing patterns to arterial oxygenation during sleep in older adults. Five older adults were monitored using standard polysomnography. Records were divided into 5-min segments and breathing patterns identified based on the level of respiratory periodicity and the variability in the frequency of breathing cycles. Standard criteria were used to determine sleep states and occurrence of EEG arousals. High respiratory periodicity was seen in 23% of the segments, whereas 24% had low respiratory periodicity with minimal variability in the frequency of breathing (Type A low respiratory periodicity) and 53% had low respiratory periodicity with high variability in the frequency of breathing (Type B low respiratory periodicity). Nearly all (97%) segments with high respiratory periodicity had EEG arousals, whereas fewer segments (33%) with low respiratory periodicity had arousals, regardless of the stage of sleep. Desaturations occurred more often in segments with high respiratory periodicity, F (2,4) = 57.3, p < .001, but overall, the mean SaO2 of segments with high respiratory periodicity did not differ from levels seen in segments with low respiratory periodicity, F( 2,4) = 0.77, ns. Our findings suggest that high respiratory periodicity is a common feature of EEG arousals and, in older adults, may be important for maintaining oxygen levels during desaturations during sleep.

Effect of voluntary vs. artificial activation on the relationship of muscle torque to speed

1990 ◽  
Vol 69 (6) ◽  
pp. 2215-2221 ◽  
Author(s):  
G. A. Dudley ◽  
R. T. Harris ◽  
M. R. Duvoisin ◽  
B. M. Hather ◽  
P. Buchanan
Keyword(s):  
Knee Extensor ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Angular Velocities ◽  
The Central Nervous System ◽  
The Right ◽  
Artificial Activation ◽  
Relationship Of ◽  
The Relationship ◽  
Eccentric Actions

The speed-torque relationship of the right knee extensor muscle group was investigated in eight untrained subjects (28 +/- 2 yr old). Torque was measured at a specific knee angle during isokinetic concentric or eccentric actions at nine angular velocities (0.17-3.66 rad/s) and during isometric actions. Activation was by "maximal" voluntary effort or by transcutaneous tetanic electrical stimulation that induced an isometric torque equal to 60% (STIM 1) or 45% (STIM 2) of the voluntary isometric value. Torque increased (P less than 0.05) to 1.4 times isometric as the speed of eccentric actions increased to 1.57 rad/s for STIM 1 and STIM 2. Thereafter, increases in eccentric speed did not further increase torque. Torque did not increase (P greater than 0.05) above isometric for voluntary eccentric actions. As the speed of concentric actions increased from 0.00 to 3.66 rad/s, torque decreased (P less than 0.05) more (P less than 0.05) for both STIM 1 and STIM 2 (two-thirds) than for voluntary activation (one-half). As a result of these responses, torque changed three times as much (P less than 0.05) across speeds of concentric and eccentric actions with artificial (3.4-fold) than voluntary (1.1-fold) activation. The results indicate that with artificial activation the normalized speed-torque relationship of the knee extensors in situ is remarkably similar to that of isolated muscle. The relationship for voluntary activation, in contrast, suggests that the ability of the central nervous system to activate the knee extensors during maximal efforts depends on the speed and type of muscle action performed.

The Relationship of Older Adults' Activities and Body Mass Index

2007 ◽  
Vol 20 (2) ◽  
pp. 217-234 ◽  
Author(s):  
Kristi Rahrig Jenkins ◽  
Nancy H. Fultz
Keyword(s):  
Older Adults ◽  
Body Mass Index ◽  
Body Mass ◽  
Relationship Of ◽  
The Relationship
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