Exercise as it relates to Disease/Exercise for Muscular Dystrophy: A new way to prolong independence

The following information provides an analysis of the journal article "Different Types of Upper Extremity Exercise Training in Duchenne Muscular Dystrophy: Effects on Functional Performance, Strength, Endurance, and Ambulation" by Alemdaroglu and Colleagues in 2014

What is the background to this research?

Muscular Dystrophy (MD) is a group of genetic disorders characterised by progressive muscle weakness affecting a patient's limb, axial and facial muscles to a varying degree. In specific cases, it may involve respiratory, cardiac and gastrointestinal muscles. The main determinants of a patient's functional capabilities are based on the severity, age of onset, rate of progression and complications of the disease.

Duchenne Muscular Dystrophy (DMD), a specific form of MD, is characterised by a lack of dystrophin that leads to abnormal muscle activation. This abnormality results in a progressive loss of functional capabilities, and a reduction in skeletal, respiratory and cardiac muscle strength. This progressive nature impairs a patient's ability to perform daily activities.

DMD has an incidence of 1/5000 boys. It presents in early childhood and those left untreated may become wheelchair-dependent by the age of 12-years, with a low mortality. Current literature surrounding DMD has focused on exercise related to lower-limb, trunk and respiratory muscles, whilst in recent years the importance of upper-limb weakness and need for therapy has been recognised.

Where is the research from?

This study was conducted in Turkey by Alemdaroglu, Karaduman, Tunca-Yilmaz and Topaloglu.

• Alemdaroglu has a PhD from the Faculty of Health Sciences, Physiotherapy and Rehabilitation department, Istanbul.
• Karaduman and Tunca-Yilmaz both have PhD's from the Faculty of Health Sciences, Physiotherapy and Rehabilitation Department, Ankara.
• Topaloglu is a Doctor of Medicine in the Neurological Department of the Children Hospital, Ankara.

Each researcher involved in the study has a background in neurological conditions and rehabilitation. There was no mention of any particular conflicts of interest or bias for the study.

What kind of research was this?

This is a randomised control trial (RCT) as the experimental group was compared to a control group that did not receive the intervention being examined. Participants were randomised into each group through a basic coin toss. RCT's are considered the highest level of evidence, however, the process of randomisation in this study was of low quality.

What did the research involve?

This study included 24 children aged 8–12 years whose functional levels were below average. Participants were on steroids for >6-months, ambulant, able to sit independently for at least 1-hour and able to follow instructions. Participants were assessed at baseline on muscle strength, grip strength, arm function, timed performance on specific tasks, upper-limb endurance and ambulation. The control group was provided with a home exercise program including strength and range of motion exercises and completed a daily exercise follow-up form. Those in the experimental group underwent exercise training with an arm ergometer. Exercise training was completed for an average of 40-minutes per session, three times a week for eight weeks, under Physiotherapy supervision. At completion, baseline assessments were remeasured.

The methodology of the study is of strong quality. It is clearly explained and reproducible. The limitations that presented were a small sample size and only basic randomisation was utilised. A larger sample size and further randomisation would minimise the risk of bias.

What were the basic results?

Alemdaroglu and Colleagues found that ambulation scores, endurance, arm function and proximal muscle strength improved following upper-limb training. The performance of daily activities was shown to have improvements following upper-limb training. The control group showed improvements in grip strength and muscle endurance only, with little effect on daily functioning.

Interpretation of the results found that children with DMD should have an exercise program that increases their participation and motivation. The use of an arm ergometer proved to be more enjoyable, easy to perform and advantageous for children.

The results of this study are clear and logical, using p-values and confidence intervals to determine the significance of findings from a statistical and clinical perspective.

What conclusions can we take from this?

Alemdaroglu and Colleagues concluded that it is highly recommended that exercise with an arm ergometer should be included in the rehabilitation of DMD. This exercise was proven to maintain functional performance and delay compilations related to the upper-limb, increase independence and maintain ambulation.

This study is the most recent to examine the benefits of upper-limb exercise in children with DMD. Prior to this, the "No use is disuse" study was the first to examine muscle endurance and functional benefits of low-intensity physical activity in children with DMD. It examined upper and lower-limb ergometer use in both ambulant and wheelchair-dependent children. The results suggested that such training was safe and feasible and may prevent functional decline.

Literature preceding these two articles was limited in outcome measures for upper-limb function, exercise recommendations, and protocols to maintain arm strength and increase endurance. The broader recommendations were to provide children with regular, mild, sub-maximal functional strengthening. Once the importance of upper-limb weakness was recognised, Alemdaroglu and Colleagues determined the aim of the present study to examine the effect of upper-limb exercise on function, strength, endurance and ambulation.

Practical Implications

The practical implications of this study are that, health professionals should aim to create an exercise program to enhance participation and motivation with the inclusion of upper-limb training with an arm ergometer in children with DMD. The benefits of an arm ergometer are maintaining function, delaying upper-limb complications, increasing independence and maintaining ambulation. The use of an arm ergometer has the ability to prolong independence. In some cases patients may not have access to an arm ergometer or are unable to use an arm ergometer due to contracture. Therefore, further research is needed into other potential forms of upper-limb therapy to provide similar benefits. Further research is also needed into later stages of DMD and the benefits/risks that may occur.

Further reading

For more information regarding DMD, follow the links below:

Muscular Dystrophy Australia: http://www.mda.org.au/disorders/dystrophies/dmd-bmd.asp

Duchenne Foundation Australia: https://www.duchennefoundation.org.au/understanding-duchenne/duchenne-muscular-dystrophy/what-dmd/

Standard of Care for Duchenne Muscular Dystrophy: http://www.parentprojectmd.org/site/DocServer/TREAT-NMD_DMD_interim_recommendations.pdf