Nonhemiplegic Side Strength Training After Stroke Improves Motor Function

In individuals who experience a stroke, strength training of the nonhemiplegic side (NHS) can promote the recovery of balance, mobility, and muscle strength of the paretic side, according to study findings published in the Archives of Physical Medicine and Rehabilitation.

The current study, a single-blinded (evaluator), randomized, controlled trial, was conducted at a tertiary hospital rehabilitation center, located in Sichuan Province, China, between July 2021 and December 2021. A total of 139 individuals who had experienced a first-ever stroke were recruited and randomly assigned to the trial group (n=69) or the control group (n=70). Researchers sought to observe the effect of strength training of the NHS on balance function, mobility, and muscle strength of patients who experience a stroke.

Individuals in the control group underwent usual rehabilitation training, which included step training and trunk control training in the standing position. Those in the trial group, in contrast, received strength training of the NHS, which was based on usual rehabilitation training. The NHS strength training comprised lower limb step training with resisting elastic belt and upper limb pulling elastic belt training in a standing position. For both groups, the training session lasted for 45 minutes, once daily, 5 days per week, for a total of 6 weeks.

The primary study outcome was balance function, which was evaluated with the use of a 14-item Berg Balance Scale (BBS). Each of the items on the BBS is a 5-point ordinal scale that ranges from 0 to 4, with 0 representing complete inability to complete a task and 4 representing the ability to complete a task. An individual’s total score can range between 0 and 56. An elevated score is indicative of enhanced postural control.

Secondary outcome measures included the assessment of mobility with use of the 6-minute walk test (6MWT); activities of daily living (ADL) evaluated via the modified Barthel Index (MBI); and muscle strengths of the biceps brachii, iliopsoas, and quadriceps measured using the isokinetic muscle strength testing system. All of the outcome assessments were completed by a physician or a physiotherapist at baseline and postintervention. All evaluators were blinded to the study aim and to the participants’ allocation.

The researchers found that the performance of individuals in the trial group was statistically significantly superior to that of those in the control group in BBS scores (adjusted mean difference between the groups, 6.83 points; 95% CI, 4.71-8.94; P <.001), as well as in mobility per the 6MWT (adjusted mean difference between the groups, 50.32; 95% CI, 40.58-60.05; P <.001). No significant difference was observed between the groups in ADL.

Regarding hemiplegic side (HS) muscle strength, following the intervention, participants in the trial group performed significantly better than those in the control group in terms of displaying greater muscle strength gains in the biceps brachii (9.83±3.95 vs 6.58±4.11, respectively; P <.001), iliopsoas (19.11±9.04 vs 13.08±7.85, respectively; P <.001), and quadriceps (31.68±12.16 vs 22.80±11.57, respectively; P <.001) following the intervention.

In terms of NHS muscle strength, significant enhancements in biceps brachii, iliopsoas, and quadriceps were reported in both groups following the intervention. Those in the trial group, however, performed significantly better than those in the control group.

Limitations of the present study should be noted. To begin, the researchers did not evaluate the spasticity of hemiplegic limbs, even though no record of drug use or botulinum toxin administration was shown to decrease spasticity in the trial group. Second, because differences between the 2 groups were observed only after the intervention, additional studies are warranted to elucidate the long-term rehabilitation efficacy.

“… [W]e recommend NHS strength training as a potential rehabilitation treatment item for stroke patients, even though it is opposite to the forced usage paradigm that is characteristic of most stroke rehabilitation procedures,” the researchers concluded.