Cryotherapy reduces muscle hypertonia, but does not affect lower limb strength or gait kinematics post-stroke: a randomized controlled crossover study

ABSTRACT

Background: Based on the premise that spasticity might affect gait post-stroke, cryotherapy is among the techniques used to temporarily reduce spasticity in neurological patients. This effective technique would enhance muscle performance, and ultimately, functional training, such as walking. However, understanding whether a decrease in spasticity level, if any, would lead to improving muscle performance and gait parameters is not based on evidence and needs to be clarified.

Objectives: to investigate the immediate effects of cryotherapy, applied to spastic plantarflexor muscles of subjects post-stroke, on tonus level, torque generation capacity of plantarflexors and dorsiflexors, and angular/spatiotemporal gait parameters.

Methods: Sixteen chronic hemiparetic subjects participated in this randomized controlled crossover study. Cryotherapy (ice pack) or Control (room temperature sand pack) were applied to the calf muscles of the paretic limb. The measurements taken (before and immediately after intervention) were: 1) Tonus according to the Modified Ashworth Scale; 2) Torque assessments were performed using an isokinetic dynamometer; and 3) Spatiotemporal and angular kinematics of the hip, knee, and ankle (flexion/extension), obtained using a tridimensional movement analysis system (Qualisys).

Results: Cryotherapy decreased plantarflexor tonus but did not change muscle torque generation capacity and did not affect spatiotemporal or angular parameters during gait compared to control application. These findings contribute to the evidence-based approach to clinical rehabilitation post-stroke.

Conclusions: The findings of this study suggest that cryotherapy applied to the calf muscles of subjects with chronic hemiparesis reduces muscle hypertonia but does not improve dorsiflexors and plantarflexors performance and gait parameters.

KEYWORDS:

• Muscle tonus
• muscle strength
• walking
• cold therapy
• cerebrovascular disease

Clinical Trial Registration

The trial was registered at ClinicalTrials.gov (URL: http://www.clinicaltrials.gov, registration nº NCT02736747).

Supplementary material

Supplementary data for this article can be accessed here.

Additional information

Funding

This study was supported by the São Paulo Research Foundation  / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)(grants: 2013/25805-1, 2017/13655-6, and 2014/25845-6) and National Council for Scientific and Technological Development / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)(funding: 442972/2014-8).