The criterion validity and intra-rater reliability of the Japanese version of the Functional Mobility Scale in children with cerebral palsy.

Researchers tested the Japanese version of the Functional Mobility Scale (FMS). They wanted to know if it measures the same thing as the gold-standard GMFCS in kids with cerebral palsy.

Twenty-two children, were rated twice by the same therapist. The team checked how well the FMS scores lined up with GMFCS levels and how consistent the ratings were.

FMS and GMFCS matched almost perfectly (r = 0.96). When a child was rated again two weeks later, the score stayed the same a large share of the time.

The scale sorted kids into the right mobility class: household, community, or playground walkers.

Eussen et al. (2016) also built a motor tool, Movakic, for kids with severe disabilities. Both studies used the same playbook: compare the new tool to a trusted one and check reliability. Movakic added responsiveness data; Nobuaki added cross-cultural proof.

Titlestad et al. (2019) tested VB-MAPP reliability in autism. Like the FMS, the total-score reliability was strong, but single items wobbled. The message from both: trust the full scale, not tiny pieces.

Ferron et al. (2017) looked at how we judge data patterns, not the tool itself. Together these papers show BCBAs need both solid tools (FMS) and solid rules for reading graphs (masked visual analysis).

If you serve Japanese-speaking families, you can now use the FMS with confidence. One quick 5-minute rating gives you a mobility level that matches the GMFCS and stays stable across sessions. Use it to pick goals, justify equipment, or show insurance why a gait trainer is needed.