OBJECTIVE To compare temporal activation patterns from 24 abdominal and lumbar muscles between healthy subjects and those who reported recovery from recent low back injury (LBI). DESIGN Cross-sectional comparative study. SETTING University neuromuscular function laboratory. PARTICIPANTS Healthy adult volunteers (N=81; 30 LBI, 51 asymptomatic subjects). INTERVENTIONS Trunk muscle electro...

The effects of low doses of alcohol on neural synchronization in muscular activity were investigated in ten participants during quiet standing with eyes open or closed. We focused on changes in common input to bilateral motor unit pools as evident in surface EMG recordings of lower leg extensor and flexor muscles. The extensor muscles exhibited bilateral synchronization in two distinct frequenc...

The effects of low doses of alcohol on neural synchronization in muscular activity were investigated in ten participants during quiet standing with eyes open or closed. We focused on changes in common input to bilateral motor unit pools as evident in surface electromyographic (EMG) recordings of lower leg extensor and flexor muscles. The extensor muscles exhibited bilateral synchronization in t...

Behavioral evidence has suggested that a small number of muscle synergies may be responsible for activating a variety of muscles. Nevertheless, such dimensionality reduction may also be explained using the perspective of alternative hypotheses, such as predictions based on linear combinations of joint torques multiplied by corresponding coefficients. To compare the explanatory capacity of these...

OBJECTIVE To compare trunk muscle coordination in people with and without low back pain with varying speeds of limb movement. STUDY DESIGN Abdominal and back extensor muscle activity in association with upper limb movement was compared among three speeds of movement and between people with and without low back pain. PARTICIPANTS Fourteen subjects with a history of recurrent low back pain an...

Fatigue, Abdominal muscle, EMG, co-contraction, loading Background: Low back pain (LBP) is one of the most prevalent musculoskeletal disorders. Altered movement patterns in LBP patients can reflect changes in neuromuscular control. Objective: This study aimed to assess trunk muscle electromyographic (EMG) response after trunk extensor muscle fatigue in LBP subjects. Methods: Sixteen patients wi...

Graded muscles produce small twitches in response to individual motor neuron spikes. During the early part of their contractions, contraction amplitude in many such muscles depends primarily on the number of spikes the muscle has received, not the frequency or pattern with which they were delivered. Stick insect (Carausius morosus) extensor muscles are graded and thus would likely show spike-nu...