Effects of Dance and Tai Chi on Balance and Wellbeing on Healthy Adults

A double-blind, randomised controlled trial will be adopted to evaluate the effects and efficacy of an eight-week dance intervention compare with Tai Chi and control group on physical and mental benefits.

Participants will be asked to attend baseline testing one week prior to the first session, which will include lower extremity muscle strength, balance, and mental wellbeing. Participants will also be asked to fill in the mood evaluating questionnaire before and after each session to measure the acute effect of each intervention. The first four weeks of the interventions are the learning phase, participants will mainly focus on learning the movements of dance or Tai Chi. After the last session of the fourth week and before the first session of the fifth, participants will be asked to complete the previous test procedure as the mid-term test. The last four weeks are the practising phase, participants will mainly focus on practising the learned movements with reduced direction from the instructor. The post-intervention test will be completed within one week after the last session, alongside an interview on their perceptions of the intervention.

Randomisation and blinding Participants will be randomly assigned to three groups: dance, Tai Chi, and Control group, using stratified random sampling based on sex. Participant mental wellbeing scores will be ranked from highest to lowest in each sex group before being systematically assigned to one of the three intervention groups, this will reduce potential differences in baseline data between groups. All measurements will be conducted by research assistants blinded to participants' group allocation and analysis will be carried out by statistician blinded to the group and test parameters.

Interventions Participants will complete informed consent and Physical Activity Readiness Questionnaire (PAR-Q) prior to data collection. At the first testing session basic anthropometric (stature, body mass, age) and personal information (ethnicity, activity level) will be recorded and each participant issued with an Unique Identifying Code (UIC).

The Dance Group, participants will be provided with three dance genre options to choose from, ballroom dance, street dance/Hip-pop and ballet, and the most-voted genre will be delivered. Dance sessions are instructed twice a week for eight weeks. Every session lasts 45-60 minutes, containing 5-10 minutes of warm-up and 35-55 minutes of learning or practicing. In the first four weeks, a short dance sequence will be taught and in the following four weeks, participants will mainly practicing the learnt sequence along with music.

The Tai Chi Group will be given the essential 18-form of Chen's style Tai Chi Chuan which is comparatively easier for beginners to learn the iconic forms with less movements and moderate intensity. Each session lasts 45-60 minutes, twice a week for 8 weeks. Every session contains 5-10 minutes of warm-up, 5 minutes of standing exercise with calming music, and 30-45 minutes of learning or practicing. In the first 8 sessions, 15 forms will be taught in total, averaging two forms taught every session. In the following 8 sessions, participants will practise the complete 18-form repeatedly following the lead of an instructor with background music. Each repetition takes approximately 2 minutes 20 seconds. Apart from movements, the Taoism philosophy as the origin of Tai Chi will also be embedded during the intervention.

Participants in Control Group will be told to maintain their usual lifestyle and only attend for physical assessments.

The pedagogy is also considered as a vital factor in this study. Thus, instructors should record each session and briefly summarise the teaching content, descriptions, and emphases if mentioned.

Intensity monitoring and progression While delivering both dance and Tai Chi interventions, the intensity will be monitored using sessions Rate of Perceived Exertion (sRPE) using the modified Borg scale. Given the targeted age group, instructors will maintain the intended RPE between 3 (moderate) and 5 (hard), with the arbitrary unit (A.U. = RPE × session duration in minutes) from 135 to 300. Participants are asked to provide a number from CR-10 retrospectively every session and the instructor then adjusts the training load accordingly if necessary. No progression is designed in the learning phase, only studying the planned form(s) of the day. While in the practicing phase, instructors should gradually raise the standard of movements and slower the speed of practicing the full sequence to increase the difficulty and intensity.

Outcome measures The Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS) will be utilised to evaluate participants mental wellbeing state change. The WEMWBS is a 14-item self-evaluating scale containing hedonic and eudaimonic statements such as 'I've been feeling relaxed' or 'I've been feeling close to other people'. The respondents rate each statement spontaneously with a 5-point Likert scale from 1 to 5 (none, rarely, sometimes, often, all the time), resulting in a minimum score of 14 and maximum score of 70. The higher WEMWBS score suggests the better mental wellbeing.

The Isometric Mid-Thigh Pull (IMTP) will be used to measure lower extremity maximum strength using Hawkins Dynamic force plate. It is considered as a safe, time-effective, and reliable measurement. Participants will be asked to stand on force plates with hips and knees slightly bent. The bar height is adjusted so that it is at mid-thigh height of each participant and the height recorded. The participant grips the bar with a slight pretension. The participant is to remain completely still for 2-3 seconds before and between each repetition. The participant will then be instructed to contract as hard and as fast as possible pulling against the bar and hold the maximum pull for 2-3 seconds before resting. Each participant will carry out 3 repetitions and the maximum and mean power recorded.

The Y Balance Test (YBT) will be used to assess participants' dynamic balance. Participants will be instructed to stand barefoot unilaterally on the centre of a tape-made 'Y'. While standing on one leg, participants will reach out with their non-stance leg as far as possible in the three directions of the 'Y'. No weight can be transferred to the non-stance leg. Three attempts for each direction for each leg will be taken and calculated as a percentage of their leg length; the greatest distance for each direction will be recorded. Leg length will be measured from the greater trochanter to the lateral malleolus.

The Brunel Mood Scale (BRUMS) will be used pre and post each dance or Tai Chi session to monitor participants' mood changes. The BRUMS contains 6 categories including anger, confusion, depression, fatigue, tension, and vigour, each is comprised of 4 adjectives such as panicky, exhausted, energetic, or active. Participants are asked to indicate their mood using a 5-point Likert scale (0=not at all, 1=a little, 2=moderately, 3=quite a bit, 4=extremely).