Ankle bracing, plantar-flexion angle, and ankle muscle latencies during inversion stress in healthy participants.
BACKGROUND
Ankle braces may enhance ankle joint proprioception, which in turn may affect reflexive ankle muscle activity during a perturbation. Despite the common occurrence of plantar-flexion inversion ankle injuries, authors of previous studies of ankle muscle latencies have focused on inversion stresses only.


OBJECTIVE
To examine the latency of the peroneus longus (PL), peroneus brevis (PB), and tibialis anterior (TA) muscles in response to various degrees of combined plantar-flexion and inversion stresses in braced and unbraced asymptomatic ankles.


METHODS
Repeated measures.


METHODS
University biomechanics laboratory.


METHODS
Twenty-eight healthy females and 12 healthy males (n = 40: mean age = 23.63 years, range = 19 to 30 years; height = 172.75 +/- 7.96 cm; mass = 65.53 +/- 12.0 kg).


METHODS
Participants were tested under 2 conditions: wearing and not wearing an Active Ankle T1 brace while dropping from a custom-made platform into 10 degrees , 20 degrees , and 30 degrees of plantar flexion and 30 degrees of inversion.


METHODS
The time between platform drop and the onset of PL, PB, and TA electromyographic activity was measured to determine latencies. We calculated a series of 2-way analyses of variance to determine if latencies were different between the conditions (braced and unbraced) and among the plantar-flexion angles (alpha = .05).


RESULTS
No interaction was found between condition and plantar-flexion angle. No significant main effects were found for condition or plantar-flexion angle. Overall means for braced and unbraced conditions were not significantly different for each muscle tested. Overall means for angle for the PL, PB, and TA were not significantly different.


CONCLUSIONS
Reflexive activity of the PL, PB, or TA was unaffected by the amount of plantar flexion or by wearing an Active Ankle T1 brace during an unanticipated plantar-flexion inversion perturbation.
Kernozek
Thomas
T
University of Wisconsin-La Crosse, La Crosse, WI 54601, USA. durall.chri@uwlax.edu
Durall
Christopher J
CJ
Friske
Allison
A
Mussallem
Matthew
M
D000222:Adaptation, Physiological; D000328:Adult; D000842:Ankle / Q000473:pathology*; D016512:Ankle Injuries / Q000517:prevention & control*; D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D001915:Braces; D005260:Female; D005528:Foot / Q000502:physiology*; D006801:Humans; D007593:Joint Instability; D008297:Male; D011446:Prospective Studies; D016059:Range of Motion, Articular; D011930:Reaction Time; D013178:Sports Medicine; D013997:Time Factors