scholarly journals Differences in Muscle Activation Patterns during Sit to Stand Task among Subjects with and without Intellectual Disability

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Antonio I. Cuesta-Vargas ◽  
Manuel González-Sánchez

The aim of this study is to analyse the differences in muscle activity between subjects who have intellectual disability and healthy subjects when they make the transition from sitting to standing positions. A cross-sectional study. A group of adults was divided into two subgroups: with and without intellectual disability (ID). The means of the basic features in both groups were 22.13 and 22.83 for age, 66.38 and 67.67 for weight, and 173.38 and 174.33 for height, for the ID () and without ID () groups, respectively. Each subject performed three sets of five repetitions during which, starting from sitting, they had to get up and sit on the chair. The recording of muscle activity was performed using surface electromyography taking the measures of muscle activity of different muscles of the lower limbs. The results showed differences in the pattern of muscle activity between groups during sitting to standing movement.

2020 ◽  
Vol 14 (4) ◽  
pp. 216-220
Author(s):  
Zahed Mantashloo ◽  
Heydar Sadeghi ◽  
Mehdi Khaleghi Tazji ◽  
Vanessa Rice ◽  
Elizabeth J Bradshaw

Objective: The aim of this study was to examine the effect of hyper pronated foot on postural control and ankle muscle activity during running and cutting movement (v-cut). Methods: In this Cross-Sectional study, 42 young physically active (exercising three times per week regularly) males participated in this study, including 21 with hyper-pronated feet and 21 with normal feet. Each participant completed a running and cutting task. Body postural control was measured using a force platform (1000Hz) which was synchronized with surface electromyography of selected ankle muscles. MATLAB software was used to process and analyze the data. One-away ANOVA was used to identify any differences between groups. Results: Differing muscle activation patterns in the surrounding ankle musculature (tibialis anterior, peroneus longus) through to reduced postural stability in the medial-lateral direction and increased vertical ground reaction forces were observed between groups. Conclusion: According to the obtained results it seems that subtalar hyper-pronation can be regarded as a factor affecting the biomechanics of cutting by changing activation patterns of the muscles surrounding the ankle, and reducing postural control of the body in medial-lateral direction, but not in anterior-posterior direction.


2013 ◽  
Vol 56 (5) ◽  
pp. 1441-1454 ◽  
Author(s):  
Bridget Walsh ◽  
Anne Smith

Purpose In this study, the authors determined whether basic patterns of muscle activation for speech were similar in preschool children who stutter and in their fluent peers. Method Right and left lower lip muscle activity were recorded during conversational speech and sentence repetition in 64 preschool children diagnosed as stuttering (CWS) and in 40 children who do not stutter (CWNS). Measures of electromyography (EMG) amplitude, right–left asymmetry, and bilateral coordination were computed for fluent speech. The potential presence of tremor-like oscillations during disfluencies of CWS was assessed, and EMG amplitudes of fluent and disfluent speech were compared in CWS. Results Across both speaking tasks, lip muscle activation was similar in CWS and CWNS in overall amplitude, bilateral synchrony, and degree of right–left asymmetry. EMG amplitude was reduced during disfluent compared with fluent conversational speech of CWS, and there was no evidence of tremor in the disfluencies of CWS. Conclusion These results support the assertion that stuttering in young children arises not from basic features of muscle contraction but rather from the command signals that control the timing and amplitude of muscle activity. The results indicate that no frank abnormality is present in muscle activation patterns in preschoolers who stutter.


Author(s):  
Roland van den Tillaar ◽  
Eirik Lindset Kristiansen ◽  
Stian Larsen

This study compared the kinetics, barbell, and joint kinematics and muscle activation patterns between a one-repetition maximum (1-RM) Smith machine squat and isometric squats performed at 10 different heights from the lowest barbell height. The aim was to investigate if force output is lowest in the sticking region, indicating that this is a poor biomechanical region. Twelve resistance trained males (age: 22 ± 5 years, mass: 83.5 ± 39 kg, height: 1.81 ± 0.20 m) were tested. A repeated two-way analysis of variance showed that Force output decreased in the sticking region for the 1-RM trial, while for the isometric trials, force output was lowest between 0–15 cm from the lowest barbell height, data that support the sticking region is a poor biomechanical region. Almost all muscles showed higher activity at 1-RM compared with isometric attempts (p < 0.05). The quadriceps activity decreased, and the gluteus maximus and shank muscle activity increased with increasing height (p ≤ 0.024). Moreover, the vastus muscles decreased only for the 1-RM trial while remaining stable at the same positions in the isometric trials (p = 0.04), indicating that potentiation occurs. Our findings suggest that a co-contraction between the hip and knee extensors, together with potentiation from the vastus muscles during ascent, creates a poor biomechanical region for force output, and thereby the sticking region among recreationally resistance trained males during 1-RM Smith machine squats.


2009 ◽  
Vol 101 (2) ◽  
pp. 969-979 ◽  
Author(s):  
Monica A. Gorassini ◽  
Jonathan A. Norton ◽  
Jennifer Nevett-Duchcherer ◽  
Francois D. Roy ◽  
Jaynie F. Yang

Intensive treadmill training after incomplete spinal cord injury can improve functional walking abilities. To determine the changes in muscle activation patterns that are associated with improvements in walking, we measured the electromyography (EMG) of leg muscles in 17 individuals with incomplete spinal cord injury during similar walking conditions both before and after training. Specific differences were observed between subjects that eventually gained functional improvements in overground walking (responders), compared with subjects where treadmill training was ineffective (nonresponders). Although both groups developed a more regular and less clonic EMG pattern on the treadmill, it was only the tibialis anterior and hamstring muscles in the responders that displayed increases in EMG activation. Likewise, only the responders demonstrated decreases in burst duration and cocontraction of proximal (hamstrings and quadriceps) muscle activity. Surprisingly, the proximal muscle activity in the responders, unlike nonresponders, was three- to fourfold greater than that in uninjured control subjects walking at similar speeds and level of body weight support, suggesting that the ability to modify muscle activation patterns after injury may predict the ability of subjects to further compensate in response to motor training. In summary, increases in the amount and decreases in the duration of EMG activity of specific muscles are associated with functional recovery of walking skills after treadmill training in subjects that are able to modify muscle activity patterns following incomplete spinal cord injury.


1989 ◽  
Vol 32 (2) ◽  
pp. 252-264 ◽  
Author(s):  
Anne Smith

EMG recordings were made from muscles of the jaw, lip, and neck during speech of 10 stutterers and 10 nonstutterers. One-second records of disfluent behaviors of stutterers and of fluent speech of the normal speakers were analyzed by computing cross correlations between all possible muscle pairs and spectra for each muscle channel. The cross correlation analysis indicated that for both the disfluent behavior of stutterers and the fluent speech of nonstutterers, jaw muscles (including antagonistic pairs), lip muscles, and neck muscles tend to be coactivated. Thus, no dramatic differences in muscle activation patterns were revealed in the correlational analysis. In contrast, spectral analysis revealed differences between muscle activity during disfluent behavior and fluent speech. During disfluencies the muscles of 6 of the stutterers showed large, rhythmic oscillations in the frequency range of 5 to 12 Hz. Large oscillations were not observed in this frequency range in the muscle activity of normal speakers. The oscillations in muscle activity during disfluencies generally occurred at the same frequency in the various muscle systems studied. These results suggest that diverse muscles are subject to common oscillatory synaptic drive during disfluent behaviors and that this drive is disruptive to speech production. A reasonable speculation is that the disruptive oscillatory drive is produced by tremorogenic mechanisms.


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