Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jul;235(7):2011-2026.
doi: 10.1007/s00221-017-4946-z. Epub 2017 Mar 25.

Modular organization of muscle activity patterns in the leading and trailing limbs during obstacle clearance in healthy adults

Affiliations

Modular organization of muscle activity patterns in the leading and trailing limbs during obstacle clearance in healthy adults

Michael J MacLellan. Exp Brain Res. 2017 Jul.

Abstract

Human locomotor patterns require precise adjustments to successfully navigate complex environments. Studies suggest that the central nervous system may control such adjustments through supraspinal signals modifying a basic locomotor pattern at the spinal level. To explore this proposed control mechanism in the leading and trailing limbs during obstructed walking, healthy young adults stepped over obstacles measuring 0.1 and 0.2 m in height. Unobstructed walking with no obstacle present was also performed as a baseline. Full body three-dimensional kinematic data were recorded and electromyography (EMG) was collected from 14 lower limb muscles on each side of the body. EMG data were analyzed using two techniques: by mapping the EMG data to the approximate location of the motor neuron pools on the lumbosacral enlargement of the spinal cord and by applying a nonnegative matrix factorization algorithm to unilateral and bilateral muscle activations separately. Results showed that obstacle clearance may be achieved not only with the addition of a new activation pattern in the leading limb, but with a temporal shift of a pattern present during unobstructed walking in both the leading and trailing limbs. An investigation of the inter-limb coordination of these patterns suggested a strong bilateral linkage between lower limbs. These results highlight the modular organization of muscle activation in the leading and trailing limbs, as well as provide a mechanism of control when implementing a locomotor adjustment when stepping over an obstacle.

Keywords: Adaptive locomotion; EMG activity; Motor control; Spinal cord.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Exp Brain Res. 2010 Apr;202(2):307-18 - PubMed
    1. J Neurophysiol. 2015 Nov;114(5):2867-82 - PubMed
    1. Motor Control. 2004 Apr;8(2):160-73 - PubMed
    1. Front Hum Neurosci. 2014 Jun 16;8:423 - PubMed
    1. Neuroscientist. 2006 Aug;12(4):339-48 - PubMed

LinkOut - more resources