Search results for "Ankle"

Ankle and knee extensor muscle effort during locomotion in young and older athletes : Implications for understanding age-related locomotor decline

2019

AbstractAge-related reduction in muscle force generation capacity is similarly evident across different lower limb muscle groups, yet decline in locomotor performance with age has been shown to depend primarily on reduced ankle extensor muscle function. To better understand why ageing has the largest detrimental effect on ankle joint function during locomotion, we examined maximal ankle and knee extensor force development during a two-leg hopping test in older and young men, and used these forces as a reference to calculate relative operating efforts for the knee and ankle extensors as participants walked, ran and sprinted. We found that, across locomotion modes in both age groups, ankle ex…

Antagonist mechanical contribution to resultant maximal torque at the ankle joint in young and older men.

2007

Abstract A recorded muscular torque at one joint is a resultant torque corresponding to the participation of both agonist and antagonist muscles. This study aimed to examine the effect of aging on the mechanical contributions of both plantar- and dorsi-flexors to the resultant maximal voluntary contraction (MVC) torques exerted at the ankle joint, in dorsi-flexion (DF) and plantar-flexion (PF). The estimation of isometric agonist and antagonist torques by means of an EMG biofeedback technique was made with nine young (mean age 24 years) and nine older (mean age 80 years) men. While there was a non-significant age-related decline in the measured resultant DF MVC torque (−15%; p =0.06), there…

Coactivation at the ankle joint is not sufficient to estimate agonist and antagonist mechanical contribution

2009

The aim of this study was to assess, via an elec- tromyographic (EMG) biofeedback method, the mechanical con- tribution of both agonist and antagonist muscles during maximal voluntary contraction (MVC). We compared this original method with the MVC-EMGmax ratio and the torque/EMG relationship method, both of which are commonly used to estimate antago- nist torque. The plantarflexion (PF) and dorsiflexion (DF) MVCs were measured simultaneously with EMG activity of triceps surae (TS) and tibialis anterior in 15 young adults (mean age 23 years). Antagonist torques obtained from the torque/EMG relationship and EMG biofeedback methods appeared to be similar. TS antagonist torque had a major mech…

How the ankle joint angle alters the antagonist and agonist torques during maximal efforts in dorsi- and plantar flexion

2011

The aim of this study was to assess, via an EMG bio-feedback method, the ankle joint angle effect on the agonist and antagonist torques in plantar- (PF) and dorsi-flexion (DF). The isometric PF and DF maximal voluntary contractions (MVCs) torques were measured simultaneously with surface EMG activity of triceps surae (TS) and tibialis anterior (TA) muscles in 12 young adults (mean age 27) at five different ankle joint angles. Our results showed that: (i) The coactivation level does not properly reflect the mechanical effect of the antagonist muscle, (ii) TS antagonist torque significantly altered the DF MVC-angle relationship, whereas TA antagonist torque did not influence this MVC-angle re…

Ankle impingement syndromes: classification and role of diagnostic imaging.

2010

Carotid plaque detection improves the predictve value of CHA2DS2-VASc score in patients with non-valvular atrial fibrilation: The ARAPACIS Study

2017

Abstract Background and aims Vascular disease (VD), as assessed by history of myocardial infarction or peripheral artery disease or aortic plaque, increases stroke risk in atrial fibrillation (AF), and is a component of risk assessment using the CHA 2 DS 2 -VASc score. We investigated if systemic atherosclerosis as detected by ultrasound carotid plaque (CP) could improve the predictive value of the CHA 2 DS 2 -VASc score. Methods We analysed data from the ARAPACIS study, an observational study including 2027 Italian patients with non-valvular AF, in whom CP was detected using Doppler Ultrasonography. Results VD was reported in 351 (17.3%) patients while CP was detected in 16.6% patients. Ad…

Tempo-controlled resistance training of the hip abductors and ankle dorsiflexors with light loads does not improve postural sway in older adults.

2022

The force steadiness capabilities of the hip abductors and ankle dorsiflexors can explain a significant amount of the variance in postural sway during four types of standing balance tests. Control over balance, as well as force steadiness, generally worsens with aging, although the latter can be improved with unique training interventions. The purpose of our study was to assess how tempo-controlled, light-load resistance training of the hip abductors and ankle dorsiflexors influences performance in clinical movement tests, postural sway, muscle strength, and force steadiness in older adults. Participants (n = 28, 70 +/- 7 years, 8 men) completed nine training sessions for either the hip abd…

A test of the effort equalization hypothesis in children with cerebral palsy who have an asymmetric gait.

2022

Healthy people can walk nearly effortlessly thanks to their instinctively adaptive gait patterns that tend to minimize metabolic energy consumption. However, the economy of gait is severely impaired in many neurological disorders such as stroke or cerebral palsy (CP). Moreover, self-selected asymmetry of impaired gait does not seem to unequivocally coincide with the minimal energy cost, suggesting the presence of other adaptive origins. Here, we used hemiparetic CP gait as a model to test the hypothesis that pathological asymmetric gait patterns are chosen to equalize the relative muscle efforts between the affected and unaffected limbs. We determined the relative muscle efforts for the ank…

Relationship between carotid intima-media thickness and non valvular atrial fibrillation type.

2015

OBJECTIVE: Carotid intima-media thickness (cIMT) is a surrogate marker of subclinical atherosclerosis and it is able to predict both coronary and cerebral vascular events. No data exist on the association between cIMT and non valvular atrial fibrillation (NVAF) type. We conduct this study with the aim to analyze the association between abnormal cIMT and NVAF type. METHODS: A cross-sectional study of the "Atrial fibrillation Registry for Ankle-brachial index Prevalence Assessment-Collaborative Italian Study (ARAPACIS)" has been performed. Among 2027 patients enrolled in the ARAPACIS, 673 patients, who underwent carotid ultrasound examination to assess cIMT, were included in the study. RESULT…

What are the effects of the aging of the neuromuscular system on postural stability?

2015

International audience; Aging is frequently associated with a decreased postural stability, essentially after 60 years, leading to an increased risk of falling. In this article we propose to highlight the influence of the aging of the neuromuscular system on postural stability when standing upright. To maintain balance while standing upright, human needs to control the activity of ankle muscles and particularly the plantar flexors. During the aging process, the performance of these muscles are strongly altered. It is commonly observed large deficits in elderly people with history of falls. Some authors reported an inverse correlation between the amplitude of postural sway and the capacity o…