Functional Electrical Stimulation in Chronic Ankle Instability

Immediate and Long-term Effects of Gait Training With Functional Electrical Stimulation in Subjects With Chronic Ankle Instability

Individuals with chronic ankle instability (CAI) display neuromuscular deficits such as altered control of posture and gait when compared with healthy controls. These deficits may be attributed to muscle inhibition occurring after a surrounding joint structure has been damaged. Functional electrical stimulation (FES) is the application of high-intensity intermittent electrical stimuli to generate muscle contractions that may overcome inhibition, and which is coupled with a functional task such as gait.

The current study aims to investigate the short and immediate effects of FES on gait parameters and postural control in subjects with CAI. Prior to intervention, treadmill gait will be evaluated using a motion analysis system, and postural control will be evaluated in a series of tests that measure balance, reaction time to ankle perturbation and stabilization ability after jump-landing. Then, a 20 minutes gait training with an FES device will be applied. Immediate effects of the training on gait parameters will be assessed. For medium-term effects evaluation, subjects will return for additional 7 training sessions (2 per week for 4 weeks), following by a complete measurements acquisition as prior to intervention. At six months follow-up, subjects will be contacted for collecting subjective outcomes.

Inclusion Criteria:

1. A history of at least one significant ankle sprain:

   1. At least 12 months prior to participating in the study
   2. Was characterized by inflammatory symptoms (i.e. pain and swelling)
   3. Caused at least one day of decreased physical activity

2. At least 3 months since the last acute ankle sprain that results in inflammatory symptoms and at least one interrupted day of desired physical activity.

3. History of the previously injured ankle 'giving way' at least twice during the last 6 months, and/or 'feelings of instability' and/or recurrent sprain.

4. Being able to bear full weight on the injured lower extremity with no more than mild discomfort.

5. Scoring<24 in the Cumberland Ankle Instability Tool (CAIT)

Exclusion Criteria:

1. A history of previous surgeries to a musculoskeletal structure in either lower limb.
2. A history of a fracture requiring re-alignment
3. Any acute injury to a lower limb in the last 3 months.