Exercise as it relates to Disease/Is hydrotherapy superior to conventional land-based exercise after stroke?

This is an analysis of the journal article "Hydrotherapy vs. conventional land-based exercise for improving walking and balance after stroke: a randomized controlled trial" by Zhu in 2016.

What is the background to this research?
Stroke is defined as a sudden and focal neurological syndrome due to cerebrovascular disease. Stroke substantially increases the risk of adverse health effects such as motor impairment, balance and gait deficits, which often leads to reduced ambulation and limited mobility. Many different approaches have been used to promote rehabilitation and one promising intervention that has become an increasingly popular treatment modality is hydrotherapy. The physical attributes of hydrodynamics provide environmental conditions that improve physiological processes and motor activity. For example motor and sensory stimuli during water exercises can stimulate neuroplasticity. Hydrotherapy increases skin temperature and blood supply, decreases sensitivity to pain and provides vasodilation in the periphery that accelerates muscle relaxation. Aquatic exercise has also shown to enhance motor function as well as static and dynamic balance in chronic stroke survivors. However few studies have compared the effects of short-term aquatic exercise with land-based exercise in chronic stroke survivors. A study by Zhu in 2016 investigated the effects of hydrotherapy on walking ability and balance in these patients.

Where is the research from?
Zhu conducted the study at an outpatient rehabilitation clinic based at Tianjin Huanhu Hospital in China. The research was published in Clinical Rehabilitation in 2016, a highly ranked peer review journal. The authors do not have a proven track record but are creating a reputation in the field. They have published literature this year on aquatic obstacle training and cueing strategies to improve gait in Parkinson’s disease patients, using similar methods to this study. There were no organizational or sponsorship links that may be a conflict of interest or bias in the findings.

What kind of research was this?
This study was a single blind randomised controlled trial (RCT) over four weeks consisting of exercise interventions. The patients were randomly allocated to receive the intended or standard treatment, which minimizes selection bias. An RCT is categorised as level two evidence and is considered the gold standard for clinical trials. However there are several disadvantages of an RCT such as time and costs, conflict of interest and ethics. In regards to the overall quality of this study, the PEDro scale is used as a method of critical appraisal. There was no blinding of subjects or therapists however it scored 8/10, which suggests high quality research.

What did the research involve?
Participants that met inclusion and exclusion criteria were randomly assigned into land-based therapy or hydrotherapy. A single physiotherapist underwent individual sessions with 28 patients lasting 45 minutes, conducted five days per week. After four weeks of rehabilitation, a blinded assessor evaluated functional assessments including the Berg Balance Scale (BBS), Functional Reach Test (FRT), Timed Up and Go Test (TUG) and 2-minute walk test (2MWT).

Table 1: Exercise protocol

The limitations of the study were the small sample size and lack of follow-up to evaluate the long-term effect of hydrotherapy. Future studies should target a larger patient cohort and follow-up studies to determine if short-term changes are similarly effective in the long-term. Also the purchase of aquatic treadmills may not be realistic for hospitals to due associated costs.

What were the basic results?
Allocation of patients was consistent and the participants’ characteristics did not different significantly between the two groups. The researchers interpreted the results through both intragroup and intergroup analysis. After four weeks of treatment, each outcome measures had improved significantly in both groups. When comparing the aquatic group to the control group, the improvement in the FRT and 2MWT was significantly higher. However the differences in the mean values of the improvements in the BBS and the TUG were not statistically significant. A relatively short programme of hydrotherapy exercise resulted in a large improvement in a small group of individuals with relatively high balance and walking function following a stroke. The authors did not over-emphasise the implications of their findings, as many of the improvements were statistically significant. Furthermore there were no dropouts or adverse events and all patients were fully compliant.

What conclusions can we take from this research?
Numerous studies have shown the superior effects of hydrotherapy compared to land-based treadmill training on chronic stroke patients. However Zhu was one of the first researchers to recommend balance and coordination exercises in addition to underwater treadmill exercise. The study proves that four weeks of hydrotherapy is an effective tool for improving postural balance and mobility compared to an equivalent amount of land-based therapy in chronic stroke patients. However there is a small sample size, lack of follow up and failure to combine the two groups. A similar study published this year provides additional evidence to support the use of water-based exercises in the sub-acute phase of stroke. Improvements in the BBS occurred when a combination of water and land based exercises were provided compared to hydrotherapy alone.

Practical advice
This research has shown hydrotherapy is superior to conventional land-based exercise for improving walking and balance after stroke. Although in order for this intervention to be successful, health professionals must assess the physiological benefits of a hydrotherapy pool and underwater treadmill compared to the associated costs. Future research needs to investigate how to successfully implement these strategies.

Further information/resources
For further information on stroke and the benefits of hydrotherapy read below; alternatively contact your GP for additional information.
 * Stroke overview
 * Clinical guidelines for stroke management 2017
 * Aquatic therapy for stroke
 * Hydrotherapy exercises for neurological rehabilitation