Effect of peripheral afferent alteration of the lateral ankle ligaments on dynamic stability.
BACKGROUND
The sensorimotor influence of the lateral ankle ligaments in muscle activation is unclear.


OBJECTIVE
The lateral ankle ligaments have significant sensorimotor influence on muscle activation.


METHODS
Controlled laboratory study.


METHODS
Muscle-firing characteristics in response to a high-speed inversion perturbation and during gait were assessed in 13 normal subjects. Solutions (1.5% lidocaine or a placebo of saline) were injected bilaterally into the anterior talofibular and calcaneofibular ligaments (1.5 ml per ligament) to alter peripheral afferent influence. Subjects were again tested with the same protocol.


RESULTS
The protective response of the anterior tibialis and peroneal muscles during inversion perturbation and mean muscle activation amplitude decreased during running after both injections. After injection, no significant differences were seen for muscle reflex latencies, maximum amplitude, time to maximum amplitude during inversion perturbation, or mean amplitude during walking.


CONCLUSIONS
The lateral ankle ligaments have a sensorimotor influence on muscle activation.


CONCLUSIONS
Induced edema from the injected solutions may have altered the sensorimotor influence of the lateral ankle ligaments, thereby inhibiting the dynamic ankle stabilizers. This finding suggests that dynamic stability may be compromised because of swelling after joint injury.
Myers
Joseph B
JB
Neuromuscular Research Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Riemann
Bryan L
BL
Hwang
Ji-Hye
JH
Fu
Freddie H
FH
Lephart
Scott M
SM
D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D017844:Lateral Ligament, Ankle / Q000294:innervation* / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D012018:Reflex / Q000502:physiology; D012420:Running / Q000502:physiology; D016138:Walking / Q000502:physiology