Development and Validation of the FBIndex to Determine the Risk of Falls for Patients with Neuromuscular Disorders

Currently, there are no standardised fall risk scores or guidelines on when to use appropriate assistive gait devices (AGDs) for people with neuromuscular disorders (NMDs). There is a clear medical unmet need to provide a battery of appropriate locomotor gait assessments to determine the risk of falling for patients with NMDs and give clear guidelines to prescribe an appropriate AGD.

The primary goal is to confirm whether the clinical battery assessments (Heel-Rise Test (HRT), Chair-Rise Test (CRT), Semi-tandem Stand (STS), Trunk-Rise Test (TRT), Foot-Tapping Test (FTT), Timed Up and Go (TUG), 10-Meter-Walk Test (10MWT) and 6-Minute-Walk Test (6MWT) can be validated and generalized to other NMD target populations that meet broader eligibility criteria based on used clinical assessments. The second objective of this project is to provide intra- and inter-observer reliability and test-retest reliability of included clinical assessments used to determine the risk of falling for patients with NMDs. Finally, all data will be compared with norm data from the healthy population (n=15) collected retrospectively.

The NMD people are characterised by a complex muscle weakness caused by a combination of different factors. These include reduced endurance, lack of explosive muscle force and power, intramuscular strength coordination, and reduced balance. Those parameters need to be considered when developing an appropriate fall risk score. The combination of short muscular function and balance assessments with short clinical scores, can be a new, valid approach to evaluating the patient's risk of falling. In addition, it assists in creating a quick checkup for prescribing an appropriate assistive device.

In the first part (feasibility study) of this project, the following force plate tests were identified as suitable to assess muscle power, force and balance variables: Heel-Rise Test (HRT), Chair-Rise Test (CRT), Semi-tandem Stand (STS), Trunk-Rise Test (TRT), Foot-Tapping Test (FTT). They were used as predictors to assess patients muscle weakness and disability. In addition to muscle power and force data collected on the force plate, a second rater manually evaluated the time required to perform this test using a stopwatch. Additionally, three separate tests, Timed Up and Go (TUG), 10-Meter-Walk Test (10MWT) and 6-Minute-Walk Test (6MWT), have been evaluated separately as standard care procedures. The TUG, 10MWT and 6MWT have been used to assess remaining motor skills (endurance, walking speed and coordination) that cannot be covered by HRT, CRT, STS, TRT and FTT. As a third parameter used for correlation analysis, two risk of fall scales, Falls Efficacy Scale International (FES-I) and Morse Fall Scale (MFS), have been used. The found data from the feasibility study, which is planned to be published, suggest a moderate to moderate to strong correlation between HRT, CRT, STS, TRT, FTT, TUG, 10MWT and 6MWT and the FES-I and will be used in in the follow-up study. The MFS was excluded from the final test battery due to a lack of correlation with dependent variables. Moreover, the dependent variables assessed on the force plate, HRT, CRT, STS, TRT, and FTT (power and force), were correlated with variables collected by performing the same test using only manual time. Applying muscle strength and power data on the force plate was necessary to confirm internal consistency, content and criterion validity, as well as the degree to which the HRT, CRT, STS, TRT and FTT test can be an adequate reflection of the same test data using only manual time variables, as the final Friedrich-Baur Risk of Fall Index (FBIndex) should be conducted without the force plate using only time variables.

This study decided to include more patients and more different neuromuscular diseases to assess a wider range of muscle weaknesses that can lead to falls. Moreover, the final test battery was defined, and the standardised methodological procedure was established.

Using regression and discrimination analysis, the cross-sectional construct validity of a priori hypotheses: "Is there a multiple correlation between HRT, CRT, STS, TRT, FTT, TUG, 10MWT and 6MWT with FES-I?" will be tested.

Eligibility Criteria:
Inclusion Criteria:

* Only patients with adequate cognitive and communicative function to give informed consent and to fill out the scale assessing the risk of falling will be included.

Exclusion Criteria:

* Patients who are unable to walk without AGD for at least 10 meters.
* Patients who had knee, hip or back surgery in the last three months.
* Patients who suffer from polyneuropathy or peripheral neuropathy.