Strength training in neuro-rehab

Neurological injuries, disease and disorders cause wide ranging and often profound levels of physical, cognitive and emotional disability.

Historically, neurological rehabilitation has focused upon restoration of ‘normal movement’, via low intensity physical activity and guided hands-on facilitation. More recently, the role of high intensity, activity based, task specific repetitive practice has emerged as a primary driver toward rehabilitation and recovery from neurological disability.

Whilst this mode of treatment is highly effective in improving functional performance, it often fails to effectively address a common symptom of neurological disorders and major determinant of independent function, as well as cardiovascular and metabolic health: muscle weakness. 

Muscle weakness occurs at the time of the insult to the nervous system, where the body’s ability to conduct nerve impulses between the brain and working muscles becomes impaired.

Because skeletal muscles have an adaptive response to the imposed demand, and reduced innervation results in a reduced demand, muscle atrophy and consequent weakness occurs rapidly, impacting the ability of the individual to move their limbs against gravity. Therefore, to enable individuals who have experienced neurological disability to maximise their functional capacity and independence, their muscle weakness and atrophy must be effectively addressed. This is achieved via resistance training.

Resistance training involves working the muscles against resistance. There are multiple different modes of applying resistance training, and to date research has failed to determine the most effective approach.

However, what is clear is that by making muscles stronger, individuals with neurological disabilities are fitter, stronger, healthier and more resilient to secondary complications associated with the immobility and sedentary lifestyle commonly associated with the conditions.

When considering muscle function, our skeletal muscles (the ones that move our body), work in three ways: concentrically (where the muscle shortens as it contracts), isometrically (where the muscle remains the same length as it contracts) and eccentrically (where the muscle lengthens as it contracts).

All through contraction types have critical roles to play within our daily functions and as such, should be represented within any strength training program. For example, to drink a glass of water, the muscle bending the elbow, the biceps brachii, must work concentrically to bend the arm and bring the cup toward the mouth, isometrically while the glass is held by the mouth to drink, and eccentrically to lower the glass back to the table. The inability of the biceps brachii to carry out any one of these muscle actions in a smooth and controlled manner, results in a puddle.

Next it is important to determine the mode of resistance training. Typically, the resistance training method can be either open chain, or closed chain. Open chain movements involve the movement of a limb in space, such as lifting a dumbbell. Closed chain movements involve the body being moved by a fixed limb, such as completing a push-up. Closed chain movements are often easier to perform in the instance of neurological disability, as they require less fine control due to the stability of the fixed limb.

However, especially in the case of the upper limb, much of our daily function requires strength in an open chain and so it is important to incorporate both aspects within a strength training program. The resistance component of resistance training usually involves either an external resistance (such as a dumbbell, barbell, band, kettle bell weights machine or flywheel), or the individual’s bodyweight. 

A final consideration is the dosage of the resistance training. Number of sessions per week, and repetitions (reps) and sets gain much attention in strength and conditioning literature, with different percentages of an individuals maximum load, different numbers of reps and sets to different rest intervals impacting muscle strength, power and endurance.

Strength training in people with neurological conditions has employed wide ranging protocols, with one to five sessions per week involving 40 to 80 per cent of one repetition maximum load for two to four sets of anything from five to 20 repetitions, with little consensus into the optimal approach possibly due to poor quality research trials in the field. 

However, in their 2015 literature review and meta-analysis Cruickshank et al. were able to conclude that one hour of supervised (by an appropriate professional), progressive submaximal strength training on at least two non-consecutive days per week led to improved muscle strength and other disease specific clinical features in Parkinson’s disease (mobility and disease progression) and MS (fatigue, quality of life, muscle power, maximal electromyography activity, and functional capacity).

Furthermore, Martin-Ginis et al. 2018 recommended at least two sessions per week that included 3 sets of strength training to the major functioning muscle groups at a moderate to vigorous intensity to bring about changes in cardiorespiratory fitness (when combined with aerobic fitness training) and muscle strength following spinal cord injury.

At PhysioFunction we have developed a team of exercise professionals who understand the science of resistance training and the needs of clients with neurological conditions and combined this with individualised, evidence informed strength training programmes that can be performed safely and effectively within our PFit studio, or at home.

Alongside conventional resistance training methods of bodyweight training, dumbbells, barbells, resistance bands, kettle bells etc., we also utilise the Desmotec V-Line and D-Line for eccentric flywheel training, allowing exercises to be directed towards the eccentric component of the movement, resulting in accelerated increases in muscle strength and functionally beneficial muscle function.