Introduction

Overview

Regular physical activity is essential to maintain health, functioning, quality of life and social participation. For individuals with DMD, there is uncertainty considering what type, level and intensity of exercise training are most beneficial.³

Physiotherapy is a vital component of Duchenne muscular dystrophy (DMD) management since it works to maintain muscle strength, increase mobility, and improve the general quality of life for those with the disease. Physiotherapy helps to preserve joint function, promote independence, and regain the loss of muscle strength through tailored stretches, exercises, and mobility aids.

Read on to learn about the different exercises and techniques used in DMD, as well as other strategies to enhance physical function and general health.

What is duchenne muscular dystrophy (DMD)?

Duchenne muscular dystrophy (DMD) is a hereditary muscular disease that is classified as dystrophinopathy, a category of genetic disorders marked by progressive muscle weakness. Muscle weakening in DMD patients follows a consistent, predictable pattern.

Importantly, individuals lose their capacity to walk before they reach puberty and, regrettably, have consequences like respiratory or, to a lesser extent, heart difficulties if they do not receive medical attention. As of now, there is no known cure for Duchenne muscular dystrophy (DMD). However, the use of corticosteroids and an orthopaedic approach has been shown to enhance patients' survival and quality of life, which has changed the course of the disease.¹

Characteristics of patients with DMD

DMD patients experience rapidly progressive proximal dominant muscle weakening, beginning with pelvic area weakness, lower limb pseudohypertrophy, and specific walking abnormalities that can be identified before age five. The majority of patients lose their motor abilities by nine years old which in 75% of these cases, leads to the development of musculoskeletal abnormalities. Muscle weakening eventually manifests in the cardiac and respiratory muscles as well, resulting in cardiac (25%) and/or respiratory (75%) failure and death.¹

Abnormalities that exacerbate the disease's prognosis can also occur in DMD patients. These include digestive issues like constipation or reflux, as well as nutritional issues like malnutrition or being overweight. However, it has been discovered that these people had lower bone density and a higher risk of fractures.¹

Characteristics are categorised below:

Early 

• Slow walking
• Language delay
• Developmental delay 

Intermediate

• Difficulty in walking
•  Frequent falls, 
• Unstable while walking.
• Walk on the balls of feet.
• Proximal predominant muscle atrophy 
• Calf pseudohypertrophy 

Late 

• Loss of ability to walk. 
• Weakness in the joints of the upper limb, and 
• tendon contractures
•  Heart failure 

Regardless of family history, a variety of clinical symptoms should be taken into consideration when suspecting DMD. Thus, based on clinical evidence, a muscle biopsy is regarded as a comprehensive diagnostic procedure. the joints of the upper limb¹

Role of physiotherapy in managing DMD

Supportive physiotherapy is one of the strategies used to delay contractures and extend ambulation. It also plays a vital role in the rehabilitation management of individuals with muscular dystrophy. Depending on the type of muscular dystrophy, these individuals may experience various clinical signs, such as musculoskeletal weakness, respiratory insufficiency, cardiac complications, and gastrointestinal manifestations. This intervention’s major objective is to keep unaffected muscle groups functioning as long as possible. Exercise can accelerate the breakdown of muscle fibres even when it aids in maintaining muscle function. Personalised exercise regimens along with guidance from the rehabilitation team may help patients live longer, more active, and independently, which would enhance their quality of life, depending on the severity of their ailment.² 

Muscular dystrophy progression phases can be roughly divided into ambulatory and non-ambulatory stages. Pre-symptomatic, early and late ambulatory stages, as well as early and late non-ambulatory stages, may also be included in the additional categorisation. Early ambulatory and presymptomatic stages: minimising contractures, preventative techniques to maintain muscles extensible. Promotion of healthy behaviour and exercise. Having equipment that may be adjusted is essential for promoting engagement and functionality when both the walking and non-walking phases are delayed. The provision of a suitable wheelchair and seating, along with the use of assistive technology and adaptations, are useful in enabling maximum independence in daily activities, function, and engagement.²

Types of physiotherapy techniques Used in DMD

Muscle extensibility and joint mobility training

People with muscular dystrophy have decreased muscle extensibility and joint contractures as a result of aberrant muscle activity, which causes restricted joint movement, muscle imbalance, extended static positioning, muscle imbalance, and fibrotic abnormalities in the muscle. This kind of change also affects the chest wall's movement, which makes breathing difficult. As soon as a diagnosis is made, regular stretching of the ankle, knee, and hip should start, and it should last until adulthood.²

Upper extremity stretches are crucial throughout the non-ambulatory phases. Before the loss of passive ranges of motion, a daily prophylactic home stretching exercise should be started under the guidance of physical and occupational therapists.²

Effective stretching of the musculotendinous unit requires positioning, splinting, orthoses, and standing devices in addition to passive, active, and active-assisted stretching. As standing and walking become more difficult, standing programs are recommended. In addition to stretching methods, manual therapy approaches, splinting, orthotic interventions, and serial casting are required to prevent joint contractures.²

Muscle strength and conditioning

As the condition progressively worsens, the majority of patients with muscular dystrophy will experience decreased muscle activity and increased fatigue. Physiotherapists may recommend mild, low-impact aerobic workouts to individuals with muscular dystrophy who are in the early ambulatory to early non-ambulatory phases of the disease. These exercises enhance cardiovascular function, boost muscle efficiency, and reduce tiredness. Additionally, they might suggest combining supervised sub-maximal strength training regimens with aerobic activity. It may occasionally be prolonged till the late non-ambulatory period if medically judged safe. Because of the slight risk of exercise-induced muscle injury, myoglobinuria, and subsequent overwork weakness from the degeneration of muscles linked to muscular dystrophy, supramaximal and high-intensity workouts should be avoided.²

It is possible to train in aerobic activities at a submaximal intensity of 60%–80% of the target heart rate four days a week. Treadmills are not recommended for swimming, stationary cycling, or arm ergometer use. Strength training three to five times a day at a low level of less than 50% of the individual maximum of one repetition and ten repetitions per set. Over several weeks to months, progressively raise the percentage of 1RM as tolerated. It is advised to take two to three days off between sessions in order to minimize metabolic damage in cases of muscular dystrophy.²

Fall prevention strategies

Individuals with DMD are more likely to fall because of imbalances in their muscles, irregularities in their stride, and poor coordination.. Extrinsic variables like slick floors and items on the floor that impede movement are mostly to blame for falls that happen during the ambulatory stages.2.

It is necessary to make adjustments to one's house and surroundings in addition to using assistive and adaptive devices, such as braces, canes, walkers, and hand splints, to prevent falls. Minimising sedentary activity is recommended.²

Changing things around the house, including getting rid of toys, carpets, cords, and other obstructions, and doing household chores while sitting down in a chair as opposed to standing for extended periods, can help manage fatigue. Under the guidance of the therapists, use wheelchairs and other mobility aids while learning safe transfer practices. It is important to have a railing for stair climbing. and make floor changes in the home, such as installing non-slip mats, non-slip step treads, adaptive bathing equipment, and assistance with handrails or bars when sitting and standing in the restroom. teaching patients self-care techniques including taking regular pauses when playing, taking lengthy walks, or engaging in any physical activity. To prevent the stress of rushing, it's also helpful to plan ahead for activities.²

Assistive devices and technology

In musculoskeletal management

To treat musculoskeletal problems Orthoses are useful for joint alignment, standing exercises, and the avoidance of contractures. Customised ankle-foot orthoses and knee ankle-foot orthoses made to fit each person's demands and comfort level are beneficial for training standing programs and aiding in ambulation for therapeutic purposes in the late ambulatory and early non-ambulatory stages. Patients should use hand splints and regularly stretch their fingers if there is tightness.²

In the late ambulatory and early non-ambulatory phases, standing aids such as motorized standing wheelchairs and passive standing devices are taken into account if contractures are not too severe and limit positioning.²

In functional training

The evaluation of daily living tasks and the requirement for assistive technology or adaptive equipment are both included in functional training. Assistive devices are not recommended during the ambulation phase because they restrict certain compensatory movements that are necessary for effective ambulation and cause difficulty by adding weight to the extremities. Instead, functional activity is primarily preserved by avoiding a sedentary lifestyle and engaging in recommended exercises. Sometimes, to extend their phase of ambulation, persons require knee, ankle, and foot orthoses with a locked knee.²

A lightweight mobility device is required for long-distance mobility in the early ambulatory stage. An ultra-lightweight manual wheelchair with a firm seat, backrest, and footrest is required in the late ambulatory stages to preserve lower extremity alignment and spinal symmetry.²

A manual wheelchair with specially designed seating and reclining characteristics is required during the early stages of non-ambulation. In the later stages of the non-ambulatory phase, a powered wheelchair may take its place. Wheelchairs with customized seating and power positioning components become more and more necessary as the condition progresses. These parts include of pressure-relieving cushions, hip guides, flip-down knee adductors, sturdy seats, back and lateral supports, power-adjustable seat height, and power-elevating leg rests.²

Rehabilitation assistive technology is needed for the assessment of alternate computer or environment control access, such as a tongue-touch control system, switch scanning, infrared pointing, or eye-gaze selection, as upper-extremity strength declines throughout the non-ambulatory period. Rehabilitation management in the late and non-ambulatory phases of the disease also includes bathing and bathroom equipment, environmental control options, and transfer devices such as a ceiling lift (hoist) or a hydraulic patient lift.²

Bed mobility exercises

Planning for bed mobility exercises and safe transfers will be aided by the physiotherapist's accurate assessment of the musculoskeletal system as the condition progresses. Encourage subjects to use their muscles to the fullest extent possible in the early stages and limit their use of aided mobility devices. When a person reaches the later stages of immobility, bedridden patients can benefit from the use of assistance equipment.²

Respiratory muscle training

For the first few stages, baseline pulmonary function tests are required for all individuals with muscular dystrophy. Patients who have abnormal baseline values from pulmonary function tests, wheelchair reliance, kyphoscoliosis, significant proximal weakness, or concomitant diseases that may impact ventilation should be closely watched.²

For the first few stages, baseline pulmonary function tests are required for all individuals with muscular dystrophy. Patients who have abnormal baseline values from pulmonary function tests, wheelchair reliance, kyphoscoliosis, significant proximal weakness, or concomitant diseases that may impact ventilation should be closely watched.²     

Swallowing exercise

Pharyngeal muscles also become involved in muscular dystrophy, which makes swallowing difficult. Before teaching them the exercises and swallowing techniques, a comprehensive evaluation is conducted, which will be helpful in addition to the speech therapy instruction. The pharyngeal muscles can also be stimulated to contract more actively via biofeedback stimulation.²

Pain management

Effective pain therapy requires accurately determining the cause, and it may also need careful team management. Pharmacological treatments, orthotic intervention, physical therapy, assistive technology, modified equipment, and posture correction might all be necessary. Adaptive equipment and assistive technologies should be used with a focus on the prevention and management of pain to maximise pleasant function and movement with the transfer, bathing, and toileting equipment.²

Conclusion

Exercise prescription, supervision, and guidance are crucial responsibilities of physical therapists. Minimal resistance and little to no impact are ideal for aerobic workouts. Since swimming puts less strain on the postural muscles, it is considered ideal.. It's critical to allow for rest periods and avoid being overly exhausted. It is recommended to discuss with your physical therapist and the restorative team for effective treatment.⁴