JMIR Publications

ABSTRACT

Background:

Lower limb injuries that involve partially reducing a patient’s weight bearing need to be monitored accurately.

Objective:

This study aimed to describe the design and preliminary implementation of an innovative multifunctional desktop load-measuring software that complements the GCH System 2.0 instrumented forearm crutches and monitors the loads applied to them, displaying real-time graphical and numerical information, as well as the correction of inaccuracies through feedback technology during assisted gait.

Methods:

The software covers numerous kinds of extrinsic feedback: visual, acoustic (verbal/beeps), concurrent, terminal, descriptive, etc.; and includes a clinical and research use database. An observational descriptive pilot study was conducted with 10 healthy subjects who had experience in bilateral assisted gait for partial unloads. The Wilcoxon matched-pairs signed rank-test was used to find the load accuracy evolution of each subject (changes in the loads exerted on crutches for each support), comparing their walks. A confidence level of 95% was considered, and the experimental P-value was compared to a significance level of 5%.

Results:

GCH Control Software, the multifunctional desktop complementing GCH System 2.0 instrumented forearm crutches was described. The pilot implementation of the feedback mechanism observed 96/100 load errors (29 underloading, 67 overloading) in the baseline walk (walk 0, no feedback), 7/10 subjects with crutch overloading. Errors ranged from 61.09% to 203.98% and were non-homogeneous. The double-bar feedback found 54/100 errors (24 underloading, 24 overloading) in the walk 1, 28/100 (8 underloading, 20 overloading) in the walk 2 and 14/100 (3 underloading, 11 overloading) in the walk 3. The first walk with double bar feedback (walk 1), began with errors similar to the baseline walk, generally followed by attempts at correction. Therefore, progress towards the ideal load. The Wilcoxon matched-pairs signed rank-test to evaluate each subject´s progress, showed that all participants steadily improved the accuracy of the loads applied to the crutches. Particularly subject 9 had to do extra feedback with 2 single-bar walks to focus on the total load. The participants also corrected load-balance between crutches and fluency errors. 3 subjects made 1 error of load balance and particularly subject 2 made 6 fluctuation errors during the three double-bar walks. The latter had to do extra feedback with 2 balance-bar walks to focus on the load balance.

Conclusions:

GCH Control Software proved useful for monitoring the loads exerted on the forearm crutches, providing a variety of types of feedback for correcting load accuracy, load balance between the crutches and fluency. The findings of the pilot implementation were promising, although long-last clinical trials with larger samples are needed to assess the efficacy of the different feedback mechanisms and to select the best alternatives in each case.