Neuromuscular characteristics in trained vs. sedentary male adults with intellectual disability

Abstract

Background This study aimed to explore muscle strength production and its underlying neuromuscular characteristics in sedentary and trained individuals with intellectual disability (ID) compared with healthy sedentary individuals. Methods Three adult groups (age: 25.07 ± 0.70) consisting of sedentary individuals with ID (IDSG), trained individuals with ID (IDTG) and a control group (CONT) participated in the present study. Peak torque (PT) during maximal voluntary isometric contraction, voluntary activation level (VAL), surface electromyography (sEMG) recordings, electrophysiological (Mmax) and potentiated twitch torque (PTT responses) of the knee extensor muscles and thigh muscle volume were assessed. Results Compared with CONT and IDTG, respectively, IDSG presented significantly lower PT (−48% and −42%), VAL (−24% and −9%), sEMG (−49% and −29%), Mmax (−41% and −39%) and PTT (−32% and −28%) values. These deficits were reduced between IDTG compared with CONT (i.e. PT: −10%; VAL: −16%; and sEMG: −28%) or did not differ anymore (PTT and Mmax). Normalising PT to thigh muscle volume and/or computing theoretical PT value overwhelm strength production differences between IDTG and CONT. Training background influences the outcomes with IDTG exhibiting greater PT, VAL, sEMG, Mmax and PTT than IDSG. Conclusions Strength production deficit in IDSG was related to both muscular and neural characteristics compared with healthy controls whereas this deficit mainly arises from neural characteristics for IDTG.

Gender Differences in Anthropometric, Functional Capacity Measures and Quality of Life in Individuals with Intellectual and Developmental Disabilities

“…Due to them having a sedentary and inactive lifestyle, it is clear that people with an IDD report high body mass index scores and a poor physical condition, including strength-related concerns [ 25 , 26 ]. These reduced values of physical ability variables are correlated with a decrease in their physical and functional capacities (decreasing their functional ability and achievement in carrying out the activities of daily life) [ 27 ], health, and life expectancy [ 28 ]. They are also associated with cardiovascular risk, indicating that elevated strength correlated with a reduction in waist circumference and an increase in triglycerides in children, adolescents, and adults [ 29 ].…”

Effects of a 24-week exercise program on anthropometric, body composition, metabolic status, cardiovascular response, and neuromuscular capacity, in individuals with intellectual and developmental disabilities

“…As a result of an inactive and sedentary lifestyle, it is thus evident that individuals with IDD have reduced values in all physical fitness, including strength ( Borji et al, 2014 ; Wouters et al, 2020 ). Similarly, this loss of muscle strength is strongly associated with a decline in physical and functional capacity ( Carmeli et al, 2012 ), health, and life expectancy ( Zghal et al, 2019 ). Muscle strength has been associated with cardiovascular risk, showing that higher levels of strength are associated with decreased waist circumference (WC) and triglycerides in children, adolescents, and adults ( De Lima et al, 2021 ).…”

Cut‐off points for isometric handgrip and low limb explosive strength in relation to indicators of overweight/obesity in people with intellectual disabilities: analysis by age groups

“…In addition, people with IDs have lower levels of physical fitness and functional limitations than people without disabilities (Silva et al 2017). Among the affected physical fitness, a reduction in strength production levels is observed compared with groups without disabilities, which leads to a general deterioration of health and a reduction in life expectancy (Zghal et al 2019). Likewise, this loss of muscle strength observed in people with IDs is strongly related to the decline in physical and functional capacity (Carmeli et al 2012).…”