Effect of LiFE-SePBT on Postural Stability in Community-dwelling Older Adults: an Assessor-blinded Randomised Controlled Trial (LiFE-SePBT)

5 sessions of combined Lifestyle-integrated Functional Exercise and Self-initiated Perturbation-based Balance Training (LiFE-SePBT) will be delivered. The LiFE component involves having participants embed functional exercises into their lifestyle, as well as practising recovering their balance upon self-initiated perturbation. Each session is 90 minutes long and will be hosted once every 2 weeks.

Lifestyle-integrated Functional Exercise and Self-initiated Perturbation-based Balance Exercise (LiFE-SePBT) is a synergistic fall prevention programme. LiFE programme targets generic balance and muscle strength whereas SePBT mainly influences through reactive balance.

Participants in the attention control group will receive 5 sessions of upper limb mobilisation and flexibility exercises. Each session is 90 minutes long and will be held once every 2 weeks.

Upper limb mobilisation and flexibility training, including arm circles, deltoid stretches, shoulder internal rotations, etc.

Generic balance ability will be assessed by the Mini-BESTest. Mini-BESTest can challenge balance across anticipatory postural adjustments, postural responses, sensory orientation and stability in gait, allowing for a comprehensive examination of improvements that occur in reactive control.

The number of real-life falls in months after randomization will be recorded. Fall circumstances and related injuries will be required via phone contact. A fall is defined as an event resulting in a person unintentionally coming to rest on the ground or other lower level, not as the result of a major intrinsic event (e.g., syncope, stroke, or overwhelming hazard such as an earthquake).

Dynamic balance will be assessed by Alternative Step Test (in the unit of seconds).

Balance confidence will be measured with the Chinese version of the shortened version of Activities-specific Balance Confidence Scale (ABC-6). The scale value is from 0 to 100, with higher values representing higher balance confidence.

Functional lower body strength will be assessed by Five-time Sit to Stand Test (in the unit of seconds).

Participants will be exposed to one trip-like perturbation and slip-like perturbation on each foot at an unexpected time. The number of falls upon perturbations will be recorded.

Depressive symptoms will be assessed by Five-Item Geriatric Depression Scale. Participants will be asked to answer 5 questions as yes or no. The answer "no" for the first question and "yes" for the other four questions will be evaluated for depression.

Health-related quality of life will be assessed by the EQ-5D-5L. In the EQ-5D-5L descriptive system, each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems. Each health state is identified by a five-digit code, with 11111 representing the best and 55555 the worst possible health state.

Muscle activations will be assessed by surface electromyography using an electromyography system (Trigno IM, Delsys Inc., Natick, MA, USA). Fourteen electrodes are placed bilaterally over erector spinae, rectus abdominis, gastrocnemius medialis, biceps femoris, rectus femoris, tibialis anterior, and gluteus medius according to the SENIAM guidelines (www.seniam.org) by the physical therapist.

Physical activity will be assessed by the Physical Activity Scale for the Elderly. This questionnaire will ask participants to recall their activity over the last 7-days. Activity types include sitting, walking, sport/recreation, exercise, occupational and household. A total score for physical activity can be calculated using these answers and the predetermined weights associated with each activity.

Cognitive flexibility and executive function will be assessed by Trial Making Tests A and B (in the unit of seconds).

The perceived ability to execute reactive stepping in different scenarios in real life situations via Short-Form Balance Recovery Confidence (SF-BRC) Scale. Each item is ranked from 0-10.

Exercise adherence will be measured via the Chinese version of Exercise Adherence Rating Scale (EARS-C). The total score of this scale is ranked between 0 to 24; each item is graded from 0 to 4 while item 1, 4 and 6 are reverse-scored.