Interlimb communication to the knee flexors during walking in humans
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Interlimb communication to the knee flexors during walking in humans. / Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Andersen, Jacob Buus; Sinkjær, Thomas; Nielsen, Jens Bo; Mrachacz-Kersting, Natalie.
In: Journal of Physiology, Vol. 591, No. 19, 2013, p. 4921-4935.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Interlimb communication to the knee flexors during walking in humans
AU - Stevenson, Andrew James Thomas
AU - Geertsen, Svend Sparre
AU - Andersen, Jacob Buus
AU - Sinkjær, Thomas
AU - Nielsen, Jens Bo
AU - Mrachacz-Kersting, Natalie
N1 - CURIS 2013 NEXS 169
PY - 2013
Y1 - 2013
N2 - A strong coordination between the two legs is important for maintaining a symmetric gait pattern and adapting to changes in the external environment. In humans as well as animals, receptors arising from the quadriceps muscle group influence the activation of ipsilateral muscles. Moreover, strong contralateral spinal connections arising from quadriceps and hamstrings afferents have been shown in animal models. Therefore, the aims of the present study were to assess if such connections also exist in humans and to elucidate on the possible pathways. Contralateral reflex responses were investigated in the right leg following unexpected unilateral knee joint rotations during locomotion in either the flexion or extension direction. Strong reflex responses in the contralateral biceps femoris (cBF) muscle with a mean onset latency of 76 ± 6 ms were evoked only from ipsilateral knee extension joint rotations in the late stance phase. To investigate the contribution of a transcortical pathway to this response, transcranial magnetic (TMS) and electrical (TES) stimulation were applied. Motor evoked potentials (MEPs) elicited by TMS, but not TES, were facilitated when elicited at the time of the cBF response to a greater extent than the algebraic sum of the cBF reflex and MEPs elicited separately, indicating that a transcortical pathway likely contributes to this interlimb reflex. The cBF reflex response may therefore be integrated with other sensory input, allowing for more flexible responses. We hypothesize that the cBF reflex response may be a preparation of the contralateral leg for early load bearing, slowing the forward progression of the body in order to maintain dynamic equilibrium during walking.
AB - A strong coordination between the two legs is important for maintaining a symmetric gait pattern and adapting to changes in the external environment. In humans as well as animals, receptors arising from the quadriceps muscle group influence the activation of ipsilateral muscles. Moreover, strong contralateral spinal connections arising from quadriceps and hamstrings afferents have been shown in animal models. Therefore, the aims of the present study were to assess if such connections also exist in humans and to elucidate on the possible pathways. Contralateral reflex responses were investigated in the right leg following unexpected unilateral knee joint rotations during locomotion in either the flexion or extension direction. Strong reflex responses in the contralateral biceps femoris (cBF) muscle with a mean onset latency of 76 ± 6 ms were evoked only from ipsilateral knee extension joint rotations in the late stance phase. To investigate the contribution of a transcortical pathway to this response, transcranial magnetic (TMS) and electrical (TES) stimulation were applied. Motor evoked potentials (MEPs) elicited by TMS, but not TES, were facilitated when elicited at the time of the cBF response to a greater extent than the algebraic sum of the cBF reflex and MEPs elicited separately, indicating that a transcortical pathway likely contributes to this interlimb reflex. The cBF reflex response may therefore be integrated with other sensory input, allowing for more flexible responses. We hypothesize that the cBF reflex response may be a preparation of the contralateral leg for early load bearing, slowing the forward progression of the body in order to maintain dynamic equilibrium during walking.
U2 - 10.1113/jphysiol.2013.257949
DO - 10.1113/jphysiol.2013.257949
M3 - Journal article
C2 - 23918771
VL - 591
SP - 4921
EP - 4935
JO - The Journal of Physiology
JF - The Journal of Physiology
SN - 0022-3751
IS - 19
ER -
ID: 48863403