The muscle shortening maneuver in individuals with stroke: a consideration-of-concept randomized pilot trial

ABSTRACT

Background and Purpose

The Muscle Shortening Maneuver (MSM) is derived from Feldman’s λ model of motor control, and seems to induce a more balanced agonist- antagonist-muscular action. The hypothesized mechanism of action is a modulation of the Tonic Stretch Reflex Threshold (TSRT). We designed a pilot, randomized trial aimed to explore the mechanisms of action of the technique. An ancillary objective was to research the implementation of the MSM as a stroke rehabilitation intervention.

Methods

A sample of 10 participants with chronic stroke was enrolled and randomly assigned to MSM (n, 5) or conventional physical therapy (CPT) (n, 5) treatments. The TSRTs were assessed by the Montreal Spasticity Measure device. A selection of clinical and instrumental outcome measures was taken to investigate function and activity levels. Data were collected at baseline, end-of-treatment, and one month after the end-of-treatment.

Results

No adverse events were observed. In both between- and within-group post-treatment assessments, in the affected ankle the MSM group showed decreased TSRTs of the plantar flexor, increased strength of the dorsiflexor and active range of motion; also, the time needed to perform the Timed Up and Go test decreased. No changes were evident across assessments in the CPT group.

Discussion and Conclusions

The MSM seems able to modulate the TSRTs in individuals with stroke. Although with the limitations due to the pilot design, the variation in participants’ responses appear to be promising. Many methodological issues have to be clarified and specified conceiving the progression toward a confirmatory trial.

KEYWORDS:

• Stroke
• spasticity
• motor control
• muscle shortening maneuver
• tonic stretch reflex threshold
• plantar flexors muscles
• rehabilitation

Acknowledgments

The authors of this study acknowledge their gratitude to Mindy Levin Full Professor, School of Physical and Occupational Therapy, McGill University, Montreal (CAN), for her constant support and especially for making her great knowledge of the theoretical basis of motor control and their applications available to us in carrying out this clinical study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors did not receive support from any organization for the submitted work.