Ankle strength and force sense after a progressive, 6-week strength-training program in people with functional ankle instability.
BACKGROUND
Although strength training is commonly used to rehabilitate ankle injuries, studies investigating the effects of strength training on proprioception have shown conflicting results.


OBJECTIVE
To determine the effects of a 6-week strength-training  protocol on force sense and strength development in participants with functional ankle instability.


METHODS
Randomized controlled clinical trial.


METHODS
University athletic training research laboratory.


METHODS
A  total of 40 participants with functional ankle instability were recruited. They were randomly placed into a training group (10 men, 10 women: age = 20.9 ± 2.2 years, height = 76.4 ± 16.1 cm, mass = 173.0 ± 7.9 kg) or control group (10 men, 10 women: age = 20.2 ±  2.1 years, height = 78.8 ± 24.5 cm, mass = 173.7 ± 8.2 kg).


METHODS
Participants in the training group performed strength exercises with the injured ankle 3 times per week for 6 weeks. The protocol consisted of a combination of rubber exercise bands  and the Multiaxial Ankle Exerciser, both clinically accepted strengthening methods for ankle rehabilitation. The progression of this protocol provided increasingly resistive exercise as participants changed either the number of sets or resistance of the Thera-Band or Multiaxial Ankle Exerciser. Main  Outcome Measure(s): A load cell was used to measure strength and force sense. Inversion and eversion strength was recorded to the nearest 0.01 N. Force-sense reproduction was measured at 2 loads: 20% and 30% of maximal voluntary isometric contraction.


RESULTS
Increases  in inversion (F(1,38) = 11.59, P < 0.01, η(p)(2) = 0.23, power = 0.91) and eversion (F(1,38) = 57.68, P < .01, η(p)(2) = 0.60, power = 0.99) strength were found in the training group at the posttest when compared  with the control group. No significant improvements were noted in force-sense reproduction for either group.


CONCLUSIONS
Strength training at the ankle increased strength but did not improve force sense.
Athletic Training Research Laboratory, Indiana University, 2805 East Tenth Street, Bloomington, IN 47408, USA.
Brent I
BI
Smith
Carrie L
CL
Docherty
Janet
J
Simon
Joanne
J
Klossner
John
J
Schrader
D000842:Ankle; D016512:Ankle Injuries / Q000503:physiopathology / Q000534:rehabilitation* / Q000628:therapy*; D000843:Ankle Joint; D015444:Exercise; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000534:rehabilitation*; D008297:Male; D053580:Muscle Strength; D011434:Proprioception; D055070:Resistance Training; D055815:Young Adult