Randomization, allocation concealment, and assessor blinding
The middle-aged and older adults were screened by three experienced physiotherapists. Eligible participants were randomly assigned to either the VT or control group. The randomization process involved the use of sealed, opaque envelopes prepared by an independent person to ensure concealed allocation. The first author performed concealed allocation, including the opening of the envelopes. A social worker from the HKCS, who was not a study participant, organized the VT training sessions. The assessors included physiotherapists and research assistants who were blinded to the group allocation; they assessed the included participants before and after the intervention period. The participants were reminded not to disclose their group allocation information to the assessors to ensure assessor blinding.