Effects of Hip Strength Training and Neuromuscular Electrical Stimulation on Functional Ankle Instability

Primary outcomes

1. Cumberland Ankle Instability Tool (CAIT) score

   Time frame: Subjects were asked to test 1 time for 10 min before and after the intervention.

   Using the CAIT score reflects the participant's subjective level of perceived stability of the ankle joint. The questionnaire contains 9 questions related to ankle function, mainly about ankle stability, pain and ankle sprains during daily activities, such as walking, running, descending stairs, and standing on one or two legs, with scores ranging from 0 to 30. The higher the score, the better the ankle stability.

2. Dynamic and static balance

   Time frame: Subjects were asked to test 1 time for 20 min before and after the intervention.

   The Tecnobody PK254P Balance Tester was used to perform static postural stability tests and dynamic postural stability tests to assess the subject's static and dynamic balance abilities. Static Postural Stability Test and Dynamic Postural Stability Test to assess the static and dynamic balance ability of the subjects. Static balance was measured by the pre The static balance ability was measured by the standard deviation in the forward and backward directions, the standard deviation in the left and right directions, the area of the movement ellipse and the circumference of the movement trajectory. The static balance ability was measured by the total stability index, anterior-posterior axis stability index, and left-right axis stability index.

3. Muscle activation

   Time frame: Subjects were asked to test 1 time for 40 min before and after the intervention.

   The electromyographic signals of gluteus medius, gluteus maximus, tibialis anterior, peroneus longus and gastrocnemius were collected by Noraxon ultium wireless surface electromyography to analyze the total amount of discharges of the motor units of the target muscles when the target muscles were involved in the activity, so as to reflect the degree of activation of the motor units of the target muscles in the course of the exercise. The test index is the Root Mean Square (RMS) of the target muscles before and after the landing moment of the single-leg vertical jump test.

4. Joint position sense

   Time frame: Subjects were asked to test 1 time for 20 min before and after the intervention.

   Plantarflexion, dorsiflexion, inversion and eversion joint positional perception tests in active mode at the affected ankle joint were performed using the Humac Norm Multi-Joint Isokinetic Test and Training System to assess the subject's proprioception. Absolute Errors (AE) between the values of the active inversion and active valgus position sense tests and the values requested by the tester were measured.

5. Hip isometric strength

   Time frame: Subjects were asked to test 1 time for 20 min before and after the intervention.

   The Humac Norm model multi-joint isokinetic testing apparatus was used to perform hip abductor and extensor strength on the affected side in order to assess the subject's hip abductor and extensor strength. Peak Torque (PT), Relative Peak Torque to Body Weight (PT/BW), and Total Work (TW) were measured during centripetal contraction at 60°/s and 180°/s angular velocities.

6. Ankle isometric strength

   Time frame: Subjects were asked to test 1 time for 20 min before and after the intervention.

   Ankle dorsiflexion, plantarflexion, inversion and valgus isokinetic strengths were measured using the Humac Norm Multi-Joint Isokinetic Testing Instrument. Peak Torque (PT), Relative Peak Torque to Body Weight (PT/BW), and Total Work (TW) were measured during centripetal contraction at 60°/s and 180°/s angular velocities.