Rapid torque development in older female fallers and nonfallers: A comparison across lower-extremity muscles

LaRoche, Dain P.; Cremin, Kim A.; Greenleaf, Brittnee; Croce, Ronald V.

doi:10.1016/j.jelekin.2009.08.004

Cited by 134 publications

(116 citation statements)

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“…Ankle joint functional capacity (high rate of development in muscle activation and high plantarflexor moment) is important in regaining balance after tripping (Pijnappels et al 2005a;Pijnappels et al 2005b) and has been reported to have decreased in elderly fallers compared to non-fallers (LaRoche et al 2010). In addition, ankle joint functional capacity is the weakest link in elderly during walking (Beijersbergen et al 2013;Clark et al 2013), which is a prerequisite for independent living and the most common form of physical activity among elderly.…”

Section: Introductionmentioning

confidence: 99%

Neuromuscular mechanics and hopping training in elderly

et al. 2014

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Phone +358-40-8053384 merja.hoffren@jyu.fi 2 ABSTRACT Purpose: The present study examined the effects of repetitive hopping training on muscle activation profiles and fascicletendon interaction in the elderly.Methods: 20 physically active elderly men were randomly assigned for training (TG) and control groups (CG). TG performed supervised bilateral short contact hopping training with progressively increasing training volume. Measurements were performed before the training period (BEF) as well as after 2 weeks (2W) and 11 weeks (11W) of training. During measurements the gastrocnemius medialis -muscle (GaM) fascicle and its outer Achilles tendon length changes during hopping were examined by ultrasonography together with electromyographic (EMG) activities of calf muscles, kinematics, and kinetics.Results: At 2W the ankle joint stiffness was increased by 21.0 ± 19.3 % and contact time decreased by 9.4 ± 7.8 % in TG.Thereafter, from 2-11W the jumping height increased 56.2 ± 18.1 % in TG. Simultaneously tendon forces increased 24.3 ± 19.0 % but tendon stiffness did not change. GaM fascicles shifted to shorter operating lengths after training without any changes in their length modifications during the contact phase of hopping. Normalized EMG amplitudes during hopping did not change with training.Conclusions: The present study shows that 11 weeks of hopping training improves the performance of physically active elderly men. This improvement is achieved with shorter GaM operating lengths and therefore increased fascicle stiffness and improved tendon utilization after training. Based on these results hopping training could be recommended for healthy fit elderly to retain and improve rapid force production capacity.

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Section: Introductionmentioning

confidence: 99%

Neuromuscular mechanics and hopping training in elderly

et al. 2014

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“…The speed at which joint strength is produced is an important factor related to unsteadiness, with a slower generation of joint strength indicative of a higher risk of falling (9)(10)(11). When walking on stairs, and particularly when walking down stairs, it is very difficult to recover balance following a moment of unsteadiness.…”

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Contributory Factors to Unsteadiness During Walking Up and Down Stairs in Patients With Diabetic Peripheral Neuropathy

et al. 2014

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OBJECTIVEAlthough patients with diabetic peripheral neuropathy (DPN) are more likely to fall than age-matched controls, the underlying causative factors are not yet fully understood. This study examines the effects of diabetes and neuropathy on strength generation and muscle activation patterns during walking up and down stairs, with implications for fall risk. RESEARCH DESIGN AND METHODSSixty-three participants (21 patients with DPN, 21 diabetic controls, and 21 healthy controls) were examined while walking up and down a custom-built staircase. The speed of strength generation at the ankle and knee and muscle activation patterns of the ankle and knee extensor muscles were analyzed. RESULTSPatients with neuropathy displayed significantly slower ankle and knee strength generation than healthy controls during stair ascent and descent (P < 0.05). During ascent, the ankle and knee extensor muscles were activated significantly later by patients with neuropathy and took longer to reach peak activation (P < 0.05). During descent, neuropathic patients activated the ankle extensors significantly earlier, and the ankle and knee extensors took significantly longer to reach peak activation (P < 0.05). CONCLUSIONSPatients with DPN are slower at generating strength at the ankle and knee than control participants during walking up and down stairs. These changes, which are likely caused by altered activations of the extensor muscles, increase the likelihood of instability and may be important contributory factors for the increased risk of falling. Resistance exercise training may be a potential clinical intervention for improving these aspects and thereby potentially reducing fall risk.Diabetic peripheral neuropathy (DPN) is a chronic complication of diabetes, affecting up to 50% of older patients (1,2). It is characterized by sensory loss in the lower limbs, altered sense of joint position, and impaired muscular function, which can result in alterations to gait (1-5). Patients with neuropathy are five times more likely to fall than age-matched controls, with over half of patients reporting at least one fall per year (6,7). Falls while walking down stairs account for 60% of all fall-related deaths, making this activity 10 times more hazardous than level-ground walking (8).

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“…10 Maximum joint torque and RTD are also compromised in the lower extremities of older adults, particularly among fallers. 10 Relatively few studies have focused on changes in muscle RTD with age, but there is an estimated 3.5% decrease per year in muscle power after age 65. 5 The importance of RTD to fall prevention has been reported in the literature; higher contraction velocities have been found to be a stronger predictor than muscle strength of performance on lowerintensity functional tasks.…”

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confidence: 99%

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

Crockett¹,

Ardell²,

Hermanson³

et al. 2013

Physiotherapy Canada

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Purpose: To investigate the association of knee-extensor strength and power to performance in the 30-second sit-to-stand test (30sSTS) in healthy older adults. Method: In a cross-sectional study of 29 healthy older adults aged 60-82 years (12 male, 17 female), hierarchical regression was used to determine the relationship of knee-extensor concentric and eccentric strength, peak rate of torque development (peak RTD) using isokinetic dynamometry, and momentum variables with the number of sit-to-stand repetitions completed in 30 seconds (30sSTSreps). Results: Concentric (180 /s) and eccentric (90 / s) knee-extensor strength were significant independent predictors of 30sSTSreps after controlling for physical activity level, height and weight (adjusted R 2 ¼ 0.425, p ¼ 0.004; adjusted R 2 ¼ 0.427, p ¼ 0.004 respectively), as was concentric (90 /s) knee-extensor peak RTD (adjusted R 2 ¼ 0.424, p ¼ 0.004). Peak linear vertical momentum (PLVM) (adjusted R 2 ¼ 0.615, p < 0.001) accounted for 36% of the variance. Conclusions: Generation of PLVM is an important predictor of 30sSTSreps; knee-extensor concentric and eccentric strength and power are associated with improved performance in this common functional task. Focusing on these parameters in exercise interventions may improve functional performance and give insight into specific factors related to success on the test.Key Words: aged; biomechanics; muscle strength; muscle strength dynamometer; risk factors; sit-to-stand. RÉ SUMÉObjectif : É tudier le lien entre la force et la puissance de l'extenseur du genou et le rendement au cours d'un test assis-debout de 30 secondes (TAD30s) chez des adultes â gé s en bonne santé . Mé thode : Au cours d'une é tude transversale portant sur 29 adultes en bonne santé â gé s de 60 à 82 ans (12 hommes, 17 femmes), on a utilisé une ré gression hié rarchique pour dé terminer le lien entre la force concentrique et excentrique de l'extenseur du genou, le taux maximal de production du moment de force (RTD maximal) au moyen de la dynamomé trie isokiné tique, et les variables de la quantité de mouvement en fonction du nombre de ré pé titions assis-debout complé té es en 30 secondes (ré pTAD30s). Ré sultats : La force concentrique (180 /s) et excentrique (90 /s) de l'extenseur du genou constituait un pré dicteur indé pendant significatif de repTAD30s compte tenu du niveau d'activité physique, de la taille et du poids (R 2 rajusté ¼ 0,425, p ¼ 0,004; R 2 rajusté ¼ 0,427, p ¼ 0,004 respectivement), tout comme l'é tait le RTD de pointe concentrique (90 /s) de l'extenseur du genou (R 2 rajusté ¼ 0,424, p ¼ 0,004). La quantité de mouvement vertical liné aire de pointe (MVLP) (R 2 rajusté ¼ 0,615, p < 0,001) a repré senté 36 % de la variation. Conclusions : La production du MVLP constitue un pré dicteur important des ré pTAD30s. On é tablit un lien entre la force et la puissance concentriques et excentriques de l'extenseur du genou et une amé lioration du rendement dans cette tâ che fonctionnelle courante. La concentration de l'attention sur ...

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Rapid torque development in older female fallers and nonfallers: A comparison across lower-extremity muscles

Cited by 134 publications

References 50 publications

Neuromuscular mechanics and hopping training in elderly

Neuromuscular mechanics and hopping training in elderly

Contributory Factors to Unsteadiness During Walking Up and Down Stairs in Patients With Diabetic Peripheral Neuropathy

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

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