Therapeutic Interventions for Spinal Cord Injury

Original Editor - Naomi O'Reilly

Top Contributors - Naomi O'Reilly, Admin, Kim Jackson, Simisola Ajeyalemi, Vidya Acharya and Rucha Gadgil  

Introduction

Spinal cord injury has a significant impact on the quality of life, life expectancy and economic burden, with considerable costs associated with primary care and loss of income. While the most obvious consequence of spinal cord injury is paralysis, there are much wider consequences for many body functions including bladder, bowel, respiratory, cardiovascular and sexual function as well as social, financial and psychological implications.

Individuals with quadriplegia rank recovery of arm and hand function as a priority, while individuals with paraplegia rate recovery of sexual function as most important, when measured against recovery of bladder/bowel function, eradicating autonomic dysreflexia, improving gait and trunk stability, regaining normal sensation and eliminating chronic pain.

A wide range of therapeutic interventions addressing these and other important priorities such as the recovery of cardiovascular performance, muscular properties, and reducing spasticity are utilised in spinal cord injury Rehabilitation. Physiotherapists treat an array of different problems related to spinal cord injury and these involve many body systems, even though the underlying pathology is neurological in nature. This section provides a brief overview of some of the therapeutic approaches and the principles of physiotherapy rehabilitation for individuals with a spinal cord injury and the evidence underpinning the effectiveness of commonly used physiotherapy interventions.

Spasticity & Contracture Management

Positioning

Patients should be given individualised positioning and early mobilisation management plans as soon as possible after a neurological impairment to prevent complications and to regain function. It is based on reducing the effects of gravity on alpha motor neuron and consequently inhibiting muscle tone. Relaxation achieved by this technique is not permanent and unless motor learning or central program adaptation is actualised it is reversible. Hence, modifications in a number of systems are required for this treatment to be effective. The effects of muscle tone on autogenic inhibition, reciprocal innervation, labyrinthic or somatosensory effects and cerebellar regulation can be affected. It should be kept in mind that active participation of the patient is required for the changes in the CNS to occur and motor learning to take place. Positioning is used widely to prevent the development of contracture and to discourage unwanted reflex activity. After a spinal cord injury, muscles can be affected in various ways, causing pain, spasticity, and problems with speed and range of motion. One way to minimise these effects is to properly support, position, and align the body. Proper positioning can be useful to minimise or prevent pain and stiffness that are commonly present post-impairment. It can also regain movement that was lost, or limit future problems with movement. In addition, proper positioning has been shown to increase awareness and protection of the weaker side of the body.

Stretching

The presence of increased tone can ultimately lead to joint contracture and changes in muscle length. When we look at the use of stretch to normalise tone and maintain soft tissue length we employ a slow, prolonged stretch to maintain or prevent loss of range of motion. While the effects are not entirely clear the prolonged stretch produces inhibition of muscle responses which may help in reducing hypertonus, e.g. Bobath's NeuroDevelopmental Technique, Inhibitory Splinting and Casting Technique. It appears to have an influence on both the neural components of muscle, via the Golgi Tendon Organs and Muscle Spindles, and the structural components in the long term, via the number and length of sarcomeres.

• Muscle Immobilised Short Position = Loss of Sacromeres and Increased Stiffness related to an increase in connective tissue
• Muscle Immobilised in Lengthened Position = Increase Sacromeres

Studies in mice show that a stretch of 30 mins daily will prevent the loss of sarcomeres in the connective tissue of an immobilised muscle, although the timescale in humans may not relate directly. Stretching may be achieved through a number of methods which include;

Manual Stretching

Prolonged manual stretch may be applied manually, using the effect of body weight and gravity or mechanically, using machine or splints. Stretch should provide sufficient force to overcome hypertonicity and passively lengthen the muscle. Unlikely to provide sufficient stretch to cause a change in a joint that already has contracture.

Weight Bearing

Weight-bearing has been reported to reduce contracture in the lower limb through the use of Tilt-tables, and standing frames through a prolonged stretch. Angles are key to ensure the knees remain extended during the prolonged stretch as the force exerted on the knee can be quite high. Some research also challenges the assumption of the benefits of prolonged standing.

Splinting

Splints and casts are external devices “Splints and casts are external devices designed to apply, distribute or remove forces to or from the body in a controlled manner to perform one or both basic functions of control of body motion and alteration or prevention in the shape of body tissue.”Splinting can be used to produce low-force, long-duration stretching although there is a dearth of evidence to support this. A wide range of splints have been used to influence swelling, resting posture, spasticity, active and passive ROM.

Serial Casting

Serial casting is a common technique that is used and most effective in managing spasticity related contracture. Serial casting is a specialised technique to provide increased range of joint motion. The process involves a joint or joints that are tight which are immobilised with a semi-rigid, well-padded cast. Serial casting involves repeated applications of casts, typically every one to two weeks as the range of motion is restored. The duration of the stretch to reduce both spasticity and to prevent contracture are not yet clear from the research and require further research to determine the most appropriate technique and duration to produce the required effect.

Vibration

Muscle vibration has been used as a technique to reduce muscle tone and spasticity in individuals with neurological conditions. Vibrations of the muscle are thought to increase corticospinal excitability as well as inhibitory neuronal activity in the antagonistic muscle. Three motor effects achieved through muscle vibration have been identified;

1. Sustained contraction of the vibrated muscle via tonic vibration reflex
2. Depression of the motor neurones innervating the antagonistic muscles via reciprocal inhibition or antagonistic inhibition
3. Suppression of the monosynaptic stretch reflexes of the vibrated muscle while being vibrated.

Questions still remain as to whether vibration has any sustained effect on the muscle. Muscle Vibration is generally applied to directly to the chosen muscle or tendon and may be applied in two ways;

High Frequency

The high-frequency vibration is driven from a vibrator that optimally operates at a frequency of 100 - 200 Hz and at an amplitude of 1 – 2 mA. This type of vibration produce facilitation of muscle contraction through what is known as tonic vibration reflex. This facilitatory effect sustained for a brief time after application. Therefore it can be used for stimulating muscles whose primary function is one of tonic holding.

Low Frequency

The low-frequency stimulation occurring between 5 -50 Hz has an inhibitory effect on muscle through its activation of spindle secondary endings and the Golgi tendon organs.

While Vibration has the potential as a good treatment technique there is still limited evidence on its effectiveness the therapist must be aware of the precautions that must be considered when using it as a treatment option including heat generation at the point of application that has the potential for skin damage, particularly at high amplitude. Further studies are needed in the future well-designed trials with a bigger sample size to determine the most effective frequency, amplitude and duration of vibration application in the neurorehabilitation.

• Murillo N et al (2014). Focal vibration in neurorehabilitation. Eur J Phys Rehabil Med. Apr;50(2):231-42.

Mobility

Transfers

Wheelchair Training

Gait Training

The ability to walk independently is a prerequisite for most daily activities. The capacity to walk in a community setting requires the ability to walk at speeds that enable an individual to cross the street in the time allotted by pedestrian lights, to step on and off a moving walkway, in and out of automatic doors, walk around furniture, under and over objects and negotiate kerbs. A walking velocity of 1.1 - 1.5 m/s is considered to be fast enough to function as a pedestrian in different environmental and social contexts. The major requirements for successful walking include; 

• Support of body mass by lower limbs
• Propulsion of the body in the intended direction
• The production of a basic locomotor rhythm
• Dynamic balance control of the moving body
• Flexibility, i.e. the ability to adapt the movement to changing environmental demands and goals.

Walking dysfunction is common in individuals with an incomplete spinal cord injury, arising not only from the impairments associated with the spinal cord lesion but also from secondary cardiovascular and musculoskeletal consequences of disuse and physical inactivity. Muscle weakness and paralysis, poor motor control and soft tissue contracture are major contributors to walking dysfunction post spinal cord injury.

Overground Training

Treadmill Training

The incentive to provide a challenging environment, in which there is an opportunity to practise repetitively the missing components of gait, has underpinned another task-specific activity. This involves using a treadmill for gait re-training and also for improvements in cardiovascular function. A harness can be used for individuals with significant functional limitations, and this also offers the opportunity to grade the amount of body weight support provided. Therapists help to facilitate alternating stepping and weight-bearing, and as many as three therapists may be required to assist with the complete gait cycle. It has been suggested that treadmill training can support Gait Re-education as it allows a complete practice of the full gait cycle, with an opportunity for improvements in speed and endurance, which optimises cardiovascular fitness.

Task-specific training on a treadmill has also been shown to induce expansion of subcortical and cortical locomotion areas in individuals following stroke and spinal cord injury. It can result in an increase in cadence and a shortening of step length as compared to overground walking.

Upper Limb Management

Key muscles are innervated at each level of spinal cord injury and it is these muscles that determine the optimal level of upper limb function that individuals with a complete spinal cord injury can achieve.

Upper Limb Function Post Spinal Cord Injury

Level of Lesion	Upper Limb Function
C4 Tetraplegia	No Upper Limb Function
C5 Tetraplegia	Perform Simple Hand to Mouth Activities
C6 Tetraplegia	Tendonesis Grip
C7 Tetraplegia	Tendonesis Grip
C8 Tetraplegia	Active Grasp and Release

Understanding the way individuals with tetraplegia use their upper limbs and hands functionally is essential for effective management which includes:

• Prevention and treatment of contracture
• Prevention and treatment of musculoskeletal pain
• Management of the shoulder
• Improving strength and skill
• Promoting and preserving a tenodesis grip when appropriate
• Management of hand swelling
• Awareness of the potential for tendon transfers or electrical stimulation

Robotics

Over the past decade, robotics technologies are more commonly incorporated into the daily treatment schedule of many individuals post spinal cord injury. These interventions hold greater promise than simply replicating traditional therapy because they allow therapists an unprecedented ability to specify and monitor movement features such as speed, direction, amplitude, and joint coordination patterns and to introduce controlled perturbations into therapy.

Rehabilitation robotics is a field of research dedicated to understanding and augmenting rehabilitation through the application of robotic devices. Rehabilitation robotics includes the development of robotic devices tailored for assisting different sensorimotor functions (e.g. arm, hand, leg, ankle, development of different schemes of assisting therapeutic training, and assessment of sensorimotor performance). Rehabilitation using robotics is generally well-tolerated, and has been found to be an effective adjunct to therapy in individuals with motor impairments as a result of a spinal cord injury.

Robotic devices provide safe, intensive and task-oriented rehabilitation allowing;

1. precisely controllable assistance or resistance during movements
2. objective and quantifiable measures of subject performance
3. good repeatability
4. increased training motivation through the use of interactive biofeedback

You can read more about Robotic Rehabilitation for the Lower Extremity and Upper Extremity Rehabilitation using Robotics on Physiopedia.

Physical Activity & Exercise

Strength Training

Strength training is generally defined as training where the resistance against which a muscle generates force is progressively increased over time. The maximal weight or resistance a person can lift or move to complete the movement is defined as One Repetition Maximum (1 RM). Prescriptions of repetitions vary depending on prior experience of strength training and co-morbidities. Progressive resistance training is the most common form of strength training. It is thought to be most effective when it incorporates resistance, is appropriately progressed based on etc individuals capacity and the mode of training is similar to the task in which strength gains are required

It is more challenging to apply the principles of progressive resistance training to partially paralysed muscles because it is difficult to apply resistance when a muscle is unable to move through full range against gravity, which is a greater problem for weak and very weak muscles more than it is for muscles that are closer to normal strength. When partially paralysed muscles are strong enough to move through range against gravity the principles of progressive resistance training can be more easily followed. When partially paralysed muscles are not strong enough to move against gravity, training occurs in a gravity eliminated plane. Resistance can be added manually or by rotating the plane of movement away from the horizontal.

One example of an effective dosage of progressive resistance training is:

• 1 - 3 sets of 8 - 12 Repetitions with a rest of 1-3 minutes between sets
• A load corresponding to 8 - 12 Repetition Maximum (60-70% of 1RM)
• 2-3 times a week

Muscle hypertrophy and increased strength, along with the changes in body composition, the hormonal and nervous systems, have a positive impact on the daily activities of living and functional independence of the individuals with a spinal cord injury.

Cardiovascular Training

Respiratory Management

Pain Management

Electrotherapy

Modern electrotherapy practice needs to be evidence-based and used appropriately. Used at the right place, at the right time for the right reason, it has a phenomenal capacity to do good. Used unwisely, it will either do no good at all or worse still, make matters worse. The skill of electrotherapy is to make the appropriate clinical decision as to which modality to use and when.

Transcutaneous Electrical Nerve Stimulation

Transcutaneous Electrical Nerve Stimulation (TENS) is a method of electrical stimulation which primarily aims to provide a degree of symptomatic pain relief by exciting sensory nerves and thereby stimulating either the pain gate mechanism and/or the opioid system. The different methods of applying TENS relate to these different physiological mechanisms. The effectiveness of TENS varies with the clinical pain being treated, but research would suggest that when used ‘well’ it provides significantly greater pain relief than a placebo intervention. In the clinical context, it is most commonly assumed to refer to the use of electrical stimulation with the specific intention of providing symptomatic pain relief.

You can read more about Transcutaneous Electrical Nerve Stimulation (TENS) on Physiopedia.

Functional Electrical Stimulation

Functional Electrical Stimulation (FES), is an assistive technology that can be used to aid the recovery of muscle function post spinal cord injury. FES uses electrical pulses to stimulate motor neurons or denervated muscle fibers directly to elicit a contraction during functional activity in a weakened or paralysed limb. FES has an extensive history for its treatment of orthopaedic and neurological conditions.  It has been used since the mid 1960’s, traditionally to aid mobility through activation of tibialis anterior to help dorsiflex the foot throughout the gait cycle in individuals with foot drop and more recently it has been considered as a promising treatment modality for upper-limb recovery.  

Read more about the use of Functional Electrical Stimulation Cycling for Spinal Cord Injury on Physiopedia. 

Biofeedback

Biofeedback is the technique of using equipment to reveal to human beings some of their internal physiological events, normal and abnormal, in the form of visual and auditory signals in order to teach them to manipulate these otherwise involuntary or unfelt events by manipulating the displayed signals. The ultimate purpose is that the patient gets to know his own body signs and that he can control them consciously. In the first instance using biofeedback equipment, afterwards even without.

Further, neuromuscular training or biofeedback therapy is an instrument-based learning process that is based on “operant conditioning” techniques. The governing principle is that any behaviour - be it a complex manoeuvre such as eating or a simple task such as muscle contraction-when reinforced its likelihood of being repeated and perfected increases several-fold.

You can read more about Biofeedback on Physiopedia.

References