Simplified Tai Chi Exercises to Improve Function in People with Chronic Ankle Instability

The goal of this interventional trial is to evaluate the effectiveness of the simplified four-week Tai Chi training in improving function in people with chronic ankle instability. The main questions it aims to answer are:

1. Does the 4-week Tai Chi training increase ankle muscle activation?
2. Does the 4-week Tai Chi training enhance ankle proprioception?
3. Does the 4-week Tai Chi training improve ankle muscle strength？
4. Does the 4-week Tai Chi training boost balance performance？
5. Does the 4-week Tai Chi training enhance subjective ankle stability and quality of life?

Researchers will compare Tai Chi training to self-management to see if this Tai Chi training works to enhance ankle stability performance.

Participants will:

1. Take self-management and Tai Chi training, and each for 4 weeks
2. Visit the labs every 4 weeks for biomechanical measurements and questionnaires, totally 3 times.

Tai Chi is a traditional Chinese exercise practiced by millions worldwide to stay active and improve health. Based on muscle activation levels across the full set of movements (108 forms), we developed a simplified 16-form Tai Chi routine to enhance ankle stability for individuals with chronic ankle instability.

To evaluate the benefits of this simplified 16-form version for ankle function in people with chronic ankle instability, we are recruiting individuals managing symptoms of chronic ankle instability for a 4-week training program and assess their ankle-related function three times. All participants in this crossover study will participate in both the Tai Chi training and a self-management control trial, while maintaining their usual lifestyle and exercise routines throughout the study. All participants will complete the same training content and assessment tasks, but the timing of the Tai Chi training and self-management phases will be swapped.

The Tai Chi training includes a total of 12 sessions over 4 weeks, with three sessions per week, each lasting 1 hour (10 minutes of warm-up, 45 minutes of Tai Chi practice, and a 5-minute cool down). Each of the three functional assessments will include consistent measures, including muscle activation, proprioception, muscle strength, balance testing, and self-assessment scales (ankle function and quality of life).

Eligibility Criteria:
Inclusion criteria:

* Aged from 18 to 40
* A history of at least one significant lateral ankle sprain was associated with inflammatory symptoms (pain, swelling, etc) and disrupted activity
* The initial sprain must have occurred at least 12 months prior to study enrolment
* The most recent injury must have occurred more than 3 months prior to study enrolment
* Reports of feeling instable or "giving way" during daily activities or physical activities and experienced at least 2 episodes in the 6 months prior to study enrolment
* Scoring ≤25 on the Cumberland Ankle Instability Tool

Exclusion criteria:

* Any previous fractures or surgeries on the lower limbs
* Have other muscle, joint or nerve disorders that affect the function of the lower limbs
* Chest pain at rest, dizziness during rest, heart condition, or doctor's advice not to exercise without medical supervision
* Currently enrolled in other ankle rehabilitation programmes
* Already a Tai Chi practitioner
* Pregnant
* Allergic to adhesive tapes