Retraining and assessing hand movement after stroke using the MusicGlove: comparison with conventional hand therapy and isometric grip training

Abstract

Background: It is thought that therapy should be functional, be highly repetitive, and promote afferent input to best stimulate hand motor recovery after stroke, yet patients struggle to access such therapy. We developed the MusicGlove, an instrumented glove that requires the user to practice gripping-like movements and thumb-finger opposition to play a highly engaging, music-based, video game. The purpose of this study was to 1) compare the effect of training with MusicGlove to conventional hand therapy 2) determine if MusicGlove training was more effective than a matched form of isometric hand movement training; and 3) determine if MusicGlove game scores predict clinical outcomes.

Methods: 12 chronic stroke survivors with moderate hemiparesis were randomly assigned to receive MusicGlove, isometric, and conventional hand therapy in a within-subjects design. Each subject participated in six one-hour treatment sessions three times per week for two weeks, for each training type, for a total of 18 treatment sessions. A blinded rater assessed hand impairment before and after each training type and at one-month follow-up including the Box and Blocks (B & B) test as the primary outcome measure. Subjects also completed the Intrinsic Motivation Inventory (IMI).

Results: Subjects improved hand function related to grasping small objects more after MusicGlove compared to conventional training, as measured by the B & B score (improvement of 3.21±3.82 vs. -0.29±2.27 blocks; P=0.010) and the 9 Hole Peg test (improvement of 2.14±2.98 vs. -0.85±1.29 pegs/minute; P=0.005). There was no significant difference between training types in the broader assessment batteries of hand function. Subjects benefited less from isometric therapy than MusicGlove training, but the difference was not significant (P>0.09). Subjects sustained improvements in hand function at a one month follow-up, and found the MusicGlove more motivating than the other two therapies, as measured by the IMI. MusicGlove games scores correlated strongly with the B & B score.

Conclusions: These results support the hypothesis that hand therapy that is engaging, incorporates high numbers of repetitions of gripping and thumb-finger opposition movements, and promotes afferent input is a promising approach to improving an individual's ability to manipulate small objects. The MusicGlove provides a simple way to access such therapy.

Figure 1

The MusicGlove is a sensorized glove that requires the user to make functional gripping movements to play a customized version of the open source music game called Frets on Fire, which was inspired by Guitar Hero. When the scrolling notes on the screen reach the white marker at the bottom, the user must make a specific grip associated with each note. The five grip types associated with each notes are shown (middle). When the electrical lead on the thumb touches one of the other five leads on the fingers, a custom-made controller (right) sends event data to a computer through an HID USB protocol.

Figure 2

The three hand therapies tested; MusicGlove (left), IsoTrainer (middle) – a device that requires isometric gripping and conventional tabletop hand exercises with an experienced rehabilitation therapist (right). Training consisted of 6, one-hour long training sessions over the course of two weeks for each treatment type.

Figure 3

We developed two assessments in the music game that were administered at the beginning and end of each training session. The Dexterity test (left) contains notes on frets 1–3 that appear in a random sequence. The Speed test (right) contains notes on frets 1–5 that appear in an orderly sequence. In both assessments, notes gradually become closer together in time as the song progresses.

Figure 4

After two weeks of training with the MusicGlove, subjects demonstrated significant improvement in hand function pre- to post-assessment as measured by the Box and Block score (top left plot) and the 9 Hole Peg Test (top right plot). Participants also showed a significant improvement in these assessments while using the MusicGlove compared to the table-top exercises guided by a physical therapist (control). The bottom plot shows cumulative gains over the course of the study. Baseline gains represent the difference between assessment 2 and assessment 1. One month follow-up represents the difference between the final administered assessment and the second to last assessment following the final treatment. Treatment groups were randomized but are shown as ordered for graphical purposes. P < 0.017 is considered significant with an applied Bonferroni correction. *Significant improvement pre- to post-treatment. ^†Significant improvement between the two training types.

Figure 5

Results of the Intrinsic Motivation Inventory survey given after six training sessions with each training type. Significance measured by post-hoc Wilcoxon signed-rank test. P < 0.017 is considered significant with an applied Bonferroni correction. *Significant difference between MusicGlove and control. ^†Significant difference between MusicGlove and IsoTrainer. ^βSignificant difference between IsoTrainer and control.

Figure 6

Results of the user satisfaction survey given after all three training types were completed. Significance measured by post-hoc Wilcoxon signed-rank test. P < 0.017 is considered significant with an applied Bonferroni correction. *Significant difference between MusicGlove and control. ^†Significant difference between MusicGlove and IsoTrainer. ^βSignificant difference between IsoTrainer and control.

Figure 7

Comparison of the performance of the Dexterity test (top) and Speed test (bottom) using the MusicGlove, and the B & B clinical score. Thin lines represent game performance at the start of each day, thick lines represent a game performance at the end of each day, dashed lines represent performance during day 1, and solid lines represent performance at 6. The MusicGlove score significantly predicted B & B score in all 8 conditions.

Figure 8

Comparison of the% notes hit correct during the Speed assessment with B & B score. All five grip types were strongly correlated with B & B score. Data points represent the average of each participant’s Speed assessment performance over the course of the six training sessions.

Figure 9

MusicGlove Dexterity assessment and Speed assessment for the start (initial) and end (final) of each day of training (primary y-axis) along with grip strength measured by a dynamometer post-training (secondary y-axis) are compared with the five grip types used with the MusicGlove. Data points represent the average of all participants’ scores over the 6 training sessions. *Significant difference between adjacent grip types. ^†Significant linear relationship between game score and grip strength.