Introduction

In treating patients with neuromuscular conditions, occupational therapists (OT) are concerned with the patients’ acquisition and maintenance of skills necessary to perform daily tasks, such as feeding, dressing, grooming, toileting, functional mobility, communication, and play. This article addresses primarily upper-extremity issues faced by people with neuromuscular disorders, such as Charcot Marie Tooth (CMT), brachial plexus palsy injuries, arthrogryposis multiplex congenita (AMC), spinal muscular atrophy (SMA), and muscular dystrophy (MD).

When treating patients with neuromuscular disorders, it is a particular challenge to the treating therapist because of the lack of homogeneity in physical, cognitive, perceptual, and emotional presentation within the same diagnosis. Smith states, “the OTs view the child, the child’s environment and the interaction between the child and the environment in a holistic way.” She also states that the OT must determine whether limitations in performance are caused by the external environment (which is ever changing), intrinsic patient-centered factors, or a combination of extrinsic and intrinsic factors. The next statement by Smith clearly puts into focus the challenge for the practitioner in the treatment of the child with neuromuscular disorders when she states, “although functional performance can be divided into specific skills and skill components, it is the spirit of a child that holds these components together. The maturation of a child and the complexity of the interrelationships between mind and body and between physical and social development are beyond human analytic ability.”

Effective treatment techniques require a particular philosophy and groundwork in evidence-based research, but the treating therapist must also be willing to adapt and change therapeutic approaches as the patients’ long- and short-term physical and emotional responses warrants. The variable presentation can manifest as weakness, which may or may not be progressive. This group may include conditions with sensory loss, such as in CMT, or alterations in sensory processing, systemic sequelae, and concomitant impairment in cognitive abilities.

Historical and current treatment techniques range from neurophysiological and developmental, biomechanical, cognitive and psychosocial, and sensory integration. These treatment strategies can be divided into 3 broad categories: remedial approaches, compensatory approaches, and a combination of both. The remedial approach concerns the restoration of physiologic, cognitive/perceptual, and emotional balance via improving strength, flexibility, coordination, cognition, visual perception and the integration of environmental stimuli. The compensatory approach focuses on the continual adaptation of the environment to the person and vice versa.

The use of assistive devices and assistive technology (AT) in environmental modification has been used in OT practice for many years. This practice could include the use of low-technology devices, such as swivel spoons and button hook devices; adaptive equipment, such as a self-feeding apparatus and overhead slings; augmentative communication devices; and robots and exoskeletal systems.

Robots and therapy machines are increasingly finding their way into clinics and research facilities as a means to provide repetitive, labor-intensive therapy and AT to patients with neuromuscular disorders. Although this technology is still in its infancy and its effectiveness is still unproven, it is starting to demonstrate positive outcomes in patients with various types of broader neuromuscular conditions, including stroke, cerebral palsy, spinal cord injury (SCI), MD, and SMA.

The next section discusses the upper-extremity presentation. This discussion is followed by OT technology, techniques, and evaluations that are currently used. The last section describes the use of robots and machines in the treatment of neuromuscular disorders.

Upper-extremity presentation

Neuromuscular conditions present in 2 distinct motor patterns: (1) those that initially present with proximal weakness while sparing fine-motor muscles until later in the condition and (2) those that present with distal weakness first and are accompanied with a loss of position, kinesthetic, and proprioceptive awareness. The latter tend to affect fine-motor control, which makes simple tasks, like buttoning a shirt, arduous. The following neuromuscular conditions are considered in this article.

CMT is the most common of the hereditary motor-sensory neuropathies and presents with distal intrinsic muscle wasting and sensory disturbances.

Brachial plexus palsy injuries fall into the traumatic and obstetric category. The most common being the obstetric upper-nerve trunk injury, termed Erb palsy. Upper-trunk injuries result in weakness about the shoulder that affects arm placement, taking away a stable platform for using the distal arm, which is rich in sensory feedback. Additionally, brachial plexus injuries of the lower trunk can result in an insensate hand with no hand intrinsic muscle function.

AMC is a consequence of an intrauterine loss of movement, which results in joint contractures. Most commonly, it is the result of an intrauterine loss of anterior horn cells and, in most cases, a sparing of sensation and proprioception.

SMA is the result of a progressive loss of anterior horn cells caused by genetic mutations. It is characterized by a loss of motor power, initially affecting proximal, then progressing to distal musculature with sensory sparing.

MD is a group of hereditary muscle disorders that present with a progressive loss of muscle fibers with a resultant loss of strength proximally at first and then progressing distally. This condition also benefits from sensory and proprioceptive sparing.

Upper-extremity presentation

Neuromuscular conditions present in 2 distinct motor patterns: (1) those that initially present with proximal weakness while sparing fine-motor muscles until later in the condition and (2) those that present with distal weakness first and are accompanied with a loss of position, kinesthetic, and proprioceptive awareness. The latter tend to affect fine-motor control, which makes simple tasks, like buttoning a shirt, arduous. The following neuromuscular conditions are considered in this article.

CMT is the most common of the hereditary motor-sensory neuropathies and presents with distal intrinsic muscle wasting and sensory disturbances.

Brachial plexus palsy injuries fall into the traumatic and obstetric category. The most common being the obstetric upper-nerve trunk injury, termed Erb palsy. Upper-trunk injuries result in weakness about the shoulder that affects arm placement, taking away a stable platform for using the distal arm, which is rich in sensory feedback. Additionally, brachial plexus injuries of the lower trunk can result in an insensate hand with no hand intrinsic muscle function.

AMC is a consequence of an intrauterine loss of movement, which results in joint contractures. Most commonly, it is the result of an intrauterine loss of anterior horn cells and, in most cases, a sparing of sensation and proprioception.

SMA is the result of a progressive loss of anterior horn cells caused by genetic mutations. It is characterized by a loss of motor power, initially affecting proximal, then progressing to distal musculature with sensory sparing.

MD is a group of hereditary muscle disorders that present with a progressive loss of muscle fibers with a resultant loss of strength proximally at first and then progressing distally. This condition also benefits from sensory and proprioceptive sparing.

OT assessment

The purpose of OT assessments in neuromuscular disorders is to objectively identify those deficit areas that negatively impact occupational performance. An excellent compendium of hand therapy/upper-extremity assessment measures can be found in Goldfarb and colleagues. They identify and give a brief summary regarding general descriptions and citations for each evaluation. The evaluations are divided between criterion based with normative ranges and self-report scales. Richardson reviewed criteria for the underlying rationale for all standard assessments and standardized tests that have uniform procedures for administration and scoring. Tests can either be criterion referenced or norm referenced. Norm referenced tests refer to how the child performs relative to standard scores for age and gender. Criterion referenced tests refer to how the child’s performance relates to an expected level of performance or set criterion.

The results of the standardized assessments are important for establishing a therapeutic baseline of performance by identifying deficits in functional performance. They are also extremely helpful in establishing a rationale for the payment of services by second-party payers, therapy program efficacy, and in the establishment of treatment goals. Some of the limitations of these standardized tests are in the construct and content validity, that is, their ability to accurately assess a true relationship between score and limitation in occupational performance. The validity and reliability of a great number of these evaluations have not been studied in many populations with rare neuromuscular disorders. More systematic reviews into the reliability and construct validity of various upper-extremity assessment tools are available as references.

Although the importance of standardized testing and assessment has been established, it is by no means the only method of assessment of performance deficits in children with a neuromuscular disease. In fact, a combination of standardized testing, interpretation of skilled clinical observations, ecological assessments (contextual interaction between the child and her environment), and subjective interview of patients or caregivers are all used to capture the intricacy and nuance of functional occupational performance deficits in these patients. A comprehensive neuromuscular examination for the OT practitioner must be custom tailored for each child based on both physiologic and psychosocial variables along with the patients’ or parent’s expectations and social customs regarding the course.

The interview portion of the OT assessment is integrally important. It should assess whether the child’s symptomology has improved, stabilized, or worsened and, if so, over what time frame. It should also ascertain subjective concerns of the patients or parents. It is an opportunity to give the patients or parents an opportunity to candidly discuss contextually relevant developmental and occupational performance concerns.

In addition to the aforementioned standardized assessment tools, an OT assessment for the child may include the following parameters when applicable:

• 1.
  

  Assessment of the pain level at rest and with normal activities: numeric rating or visual analog scale for patients old enough or cognitively aware enough to conceptualize and verbalize the continuum of pain (graded from 0 [no pain] to 10 [excruciating pain]) (Other scales used to assess pain in the pediatric population can be found at the National Institutes of Health (NIH) Pain Consortium Website. Some of the scales are appropriate for children and adults and others are used for infants. Researchers at the NIH Clinical Center use the following: Wong-Baker Faces, COMFORT Scale, Crying, Requires O2, Increased vital signs, Expression, Sleeplessness [CRIES] Pain Scale, and the Faces, Legs, Activity, Cry, Consolability [FLACC] scale).

  
  
• 2.
  

  Postural analysis: cervical, thoracic, and lumbar alignment in standing, sitting, supine, prone, and quadruped positions; scapular arthrokinematics (winging, tipping, elevation at rest and in loaded positions, dyskinesis); and trunk control

  
  
• 3.
  

  Upper-extremity active and passive range of motion

  
  
• 4.
  

  Joint deformities: fixed contractures with interpretation of joint end feel, swan-neck deformities, Boutonniere deformities, Jeanne’s sign related to hyperlaxity of the thumb metacarpal phalangeal joint, intrinsic wasting, thenar wasting, hypothenar wasting, intrinsic plus or minus positioning

  
  
• 5.
  

  Assessment of sensibility: Semmes-Weinstein monofilament, 2-point discrimination, stereognosis

  
  
• 6.
  

  Coordination: dysmetria, proprioception, kinesthesia, stereognosis, static and dynamic sitting, and standing balance

  
  
• 7.
  

  Assessment of tonicity: hypotonia, hypertonia, rigidity, spasticity, mixed patterns, choreiform, athetoid (use of Ashworth scale to assess tonicity)

  
  
• 8.
  

  Assessment of reflexive integration/automatic reactions; assessment for primitive reflexive patterns present past expected age of integration or absence or delays in equilibrium and protective reactions

  
  
• 9.
  

  Transitional movement patterns: rolling, sit to prone and prone to sit, supine to sit, pull to stand and stand to sit with and without rotation

  
  
• 10.
  

  Ocular and ocular motor screening: visual focus, tracking, esotropia, exotropia, nystagmus, ptosis, enophthalmos

  
  
• 11.
  

  Functional fine-motor skills: prehension patterns, hand preference, writing and cutting skills

  
  
• 12.
  

  Strength: grip, pinch, manual muscle testing

Occupational therapy treatment

Occupational therapy treatment techniques for children with musculoskeletal are based on a multitude of factors as detailed previously in the section on assessment. One important concept when working with children with neuromuscular disorders is to determine whether the intervention implemented is to restore function and/or adapt to the environment. For those conditions that are classified as lower motor neuron diseases with a subtype of anterior horn involvement, such as SMA, care must be taken to avoid excessive fatigue during strength-training exercises because of neural rather than muscular fatigue and the potential for sarcolemmal membrane injury in response to increased mechanical loads, especially in those with rapidly progressive disease.

Remediation techniques

• 1.
  

  Range of motion: Poorer prognosis have been associated in those children who present impaired external rotation of the shoulder.

  
  
• 2.
  

  Strength: Use Thera-Bands (The Hygenic Corporation, Akron, OH, USA), light weights, and manual resistance working proximal to distal whenever possible. There seems to be no benefit from high-resistance, low-repetition resistance training because of a possibility of weakening with those with slowly progressing neuromuscular diseases. Care must be taken with individuals with rapidly progressing neuromuscular diseases because there may be a likelihood of weakening because of some strength-training exercises. However, there are no conclusive data that show an equivocal relationship between all types of strength training and the loss of strength within these populations. Prudence would dictate that all strength-training programs for both slowly progressing and rapidly progressing neuromuscular diseases are submaximal and function based (play, recreation) in nature. Light theraputty (Sammons Preston Roylan, Bolingbrook, IL, USA) can be used to enhance grip and pinch strength and light grippers during play and game activity can be used to manipulate game pieces and dice. Submaximal isometrics at varying joint angles may also be helpful as are place/hold exercises with varying degrees of gravitational offloading.

  
  
• 3.
  

  Sensory enhancement/desensitization: Techniques, such as fluidotherapy, transcutaneous electrical nerve stimulation at submotor threshold, retrograde massage, and gentle soft tissue mobilization, may be beneficial in decreasing neurogenic pain. Depending on the condition and current status of functioning sensibility, sensory retraining techniques may be beneficial.

  
  
• 4.
  

  Many remediation techniques have been used with a myriad of neuromuscular conditions in the past including the following:

  
  
  
  
  • a.
    

    Bobath or neurodevelopmental treatment in which specialized neuromuscular handling techniques can be used to facilitate postural control and movement coordination are used.

    
    
  • b.
    

    Rood techniques are used to normalize tone through the use of certain appropriately applied sensory stimuli.

    
    
  • c.
    

    Brunnstrom techniques that use reflexes, associated proprioceptive facilitation or exteroreceptive facilitation to develop muscle tension in preparation for voluntary movement.

    
    
  • d.
    

    The OT task-oriented approach incorporates a client-centered approach influenced by developmental and motor learning theories.

    
    
  • e.
    

    The Carr and Shepherd theoretical framework includes the dynamic system theory of motor control and the plasticity of central nervous system.

    
    
  • f.
    

    Constraint-induced movement therapy also uses the concept of neuroplasticity or the ability to cortically reorganize with focused concentrated therapy.

  
  

Compensatory techniques

Compensatory techniques can affect the use of assistive and adaptive equipment and alterations of the physical environment. It can have many considerations, including the following:

• •
  

  What is the gadget tolerance of the children and parents?

  
  
• •
  

  What is the weight, size, and balance of the equipment?

  
  
• •
  

  What is the expense of the equipment?

  
  
• •
  

  Is it easy to maintain and durable?

  
  
• •
  

  Does it really help?

  
  
• •
  

  Is it safe?

  
  
• •
  

  Will it accommodate a growing child?

  
  
• •
  

  Is it socially and culturally acceptable to patients, parents, or caregivers?

  
  
• •
  

  Is it contextually relevant and adaptable to a multitude of changing environments at home and in the community?

There are excellent compendiums available regarding environmental adaptations, stabilization procedures and applications, and developmental sequences.

Consideration must be given to the amount of other medical equipment the child may have when prescribing adaptive equipment. Examples of other equipment are wheelchairs, walkers, leg braces, thoracolumbosacral orthosis, nasogastric tubes, and percutaneous indwelling catheter lines. Care must be taken that any equipment given does not itself impair the use of existing equipment or be above the tolerance level of the patients or parents.

Listed later are some of the more common assistive devices and they are meant to give the reader a sense of the progression from simple to complex. Many of the assistive devices or adaptive equipment items are homemade and use simple household items, such as foam blocks and polyvinyl chloride (PVC) piping. In many cases, patients or family members give the OT many good ideas for developing and passing on assistive devices for other families with similar functional challenges.

Some of the more common types of adaptive equipment/assistive devices used are the following:

• •
  

  Built up handles on feeding, writing, and grooming implements to decrease the amount of force needed to secure and maintain grasp

  
  
• •
  

  The use of a universal cuff with feeding or writing implements when grip and pinch mechanics are impaired

  
  
• •
  

  Purchase of specialized feeding equipment (eg, Dining With Dignity [Dining With Dignity Inc, Williamsburg, Virginia], which has regular silverware that is retrofitted with bendable finger rings to slide over fingers, decreasing the need for a strong grip)

  
  
• •
  

  Attachment of feeding or writing implements onto a splint whereby gross arm movements are turned into functional tasks

  
  
• •
  

  The use of scoop dishes (one edge of the dish is built up and angled gently back toward the plate to allow patients to push the food onto the feeding implement by pushing it up against the scooped edge)

  
  
• •
  

  The use of swivel spoons (the distal portion of the spoon is attached to a swivel, allowing the spoon to be angled properly relative to the plate or bowl and be brought to the mouth without spilling if pronation or supination of the forearm is difficult)

  
  
• •
  

  The use of a spork (a combination of a spoon and a fork to allow the implement to perform multiple functions)

  
  
• •
  

  The use of Dycem (Dycem Limited, Warwick, Rhode Island) (a commercially available nonskid surface to place under eating containers, much like a place mat, to prevent the plates or bowls from sliding across table while feeding)

  
  
• •
  

  The use of rocker knives to allow a rocking motion through the use of a curvilinear blade rather than a more difficult linear cutting pattern

  
  
• •
  

  The use of a long-handled reacher to grasp objects outside of the functional range of motion (reachers with a forearm-bracing component are inherently more stable because they shift some of the load to the forearm and not directly to the radial side of the wrist)

  
  
• •
  

  The use of leg lifters to allow arm bracing and trunk control to lift legs into a car or wheelchair

  
  
• •
  

  The use of dressing sticks that have various hooks and or protrusions that enable patients to grasp and manipulate clothing items while dressing (An adjustable Swiffer [The Proctor & Gamble Company, Cincinnati, Ohio] handle with the cleaning end removed will also allow for easier manipulation of pants and other clothing items when grip is impaired [Marnie King, OT, Wilmington, Delaware, 2010, personal communication]; The handle extension can be compacted for easier storage and then extended as needed.)

  
  
• •
  

  The use of Velcro (Velcro USA Inc, Manchester, NH) fasteners for shoes, pants, and other clothing items (The incorporation of a D-ring may allow for a child to use crude grip patterns more efficiently by hooking the ring along a hand web space to allow for a more gross arm movement to complete dressing tasks when grip and pinch are impaired.)

  
  
• •
  

  The use of PVC piping to attach to the end of a faucet handle to act as an extension allowing the child to manipulate the control of water flow

  
  
• •
  

  The attachment of a light dowel to a light switch to enable a child to manipulate the lights from his or her wheelchair

  
  
• •
  

  Adaptations in seating and positioning using such devices as the Rifton Chair (Rifton Equipment, Rifton, NY, USA) and Trip Trap Chair (Chair Stokke LLC, Stamford, CT, USA), along with appropriate postural stability inserts for proper proximal stability enhancement through biomechanically proper posture

Many of these items may be combined to suit the patients’ needs and may be fabricated by the innovative OT after careful analysis of functional deficits and patient goals.

Reducing the effects of gravity are exceptionally important concepts in the development of therapy programs for individuals with neuromuscular disorders. The reduction of gravity may facilitate function by allowing weakened muscles to contract to a fuller degree and allow for better joint excursion and function. The concept of gravitational grading could be considered to be remedial or compensatory, depending on the potential for recovery of each particular condition. There are several ways in which this could be accomplished:

• 1.
  

  Foam blocks or wedges on tabletops can be used to prop arms up and allow for active-assisted or passive shoulder flexion to assist in feeding or grooming and other tasks requiring hand-to-mouth movement patterns. Shoulder flexion or hand-to-mouth patterning are then achieved by incorporating trunk flexion.

  
  
• 2.
  

  The use of an adapted scooter board with pivoting wheels may be used to facilitate the range of motion in friction-reduced planes. An excellent variation of this concept is to use a toy car or other toy with 4 wheels to replicate the scooter board. The car could be attached to the child’s extremity with Velcro splint strapping.

  
  
• 3.
  

  Positioning the child in a side-lying position with the upper extremity placed on a smooth surface, such as 1/4 inch particleboard propped up on pillows or fabricated into a sturdier bench configuration, will also enhance gravity and friction-reduced motion for shoulder forward flexion. Position the child in a supine position with the arm in horizontal abduction and external rotation on the particleboard. Shoulder abduction could then be performed. If the particleboard is supported at an oblique angle from the front axillary line, then shoulder motion could be performed in the scapular plane, which has been stated to be a more functional movement pattern for the shoulder than pure shoulder flexion or pure abduction. A pillowcase, towel, powder, or lotion could be also be used to further reduce friction (the last two methods are a bit messy). If shoulder motion is desired and there is a predominance of flexion at the biceps, then a lightweight static elbow splint, such as a pediwrap or an inflatable pneumatic cuff, may be used to keep the elbow in a static position, redirecting motion toward the shoulder. This offloading technique may be used for any functional movement pattern for the upper extremity. Depending on the potential for recovery and the existing level of strength, patients may be placed at an appropriate level within the gravity-reduction continuum that allows for maximal range of self-generated motion with minimal fatigue.

  
  
• 4.
  

  PVC pipe stands with a sturdy base can be easily fabricated and used in the bath or shower to prop arms and assist in hand-to-head bathing and grooming (Marnie King, OT, Wilmington, Delaware, 2010, personal communication). In addition, hooks and other types of securing devices can be added for storage of washrags, brushes, and so forth.

  
  
• 5.
  

  Aquatic therapy is a reasonable therapeutic medium for children who have neuromuscular diseases. A person immersed to the symphysis has effectively offloaded 40% of his or her bodyweight. When further immersed to the umbilicus, approximately 50% is offloaded. Xiphoid-level immersion offloads bodyweight by 60% or more depending on whether the arms are overhead or beside the trunk. Care must be taken, however, in incremental immersion above chest level secondarily to the effects of hydrostatic pressure and if patients have impaired respiration. The effects of water buoyancy will enable patients to contract muscles in a gravity-reduced plane and allow for range of motion and play activity.

  
  
• 6.
  

  Overhead slings can be fabricated from PVC piping. The slings can be fabricated from neoprene, fabric, or soft strapping material. They could be wrist based or forearm based depending on the level of stability desired. The slings are then connected to the PVC frame with the use of Thera-Bands and tubing, rubber bands, or other elastic medium. The patients’ hands and forearms are then suspended by the slings to allow for gravity-reduced active-assisted movement.

  
  
• 7.
  

  Counterbalanced slings consist of an arm sling attached to a frame via a cable or string using series of pulleys and a counterbalance weight to offload the weight of the upper extremity. The purpose being to allow for functional active-assisted movement in gravity-reduced planes. The use of counterbalanced slings allows motion in multiple planes but they are attached to a large frame that is bulky and often difficult to properly maneuver into biomechanically correct alignment. Additionally, the method of counterbalance weight delivery may not be as precise as needed for a zero-balance effect for the upper extremity. The slings may also tend to slip off of the forearm.

  
  
• 8.
  

  Balanced forearm orthoses (BFO) consists of an adjustable forearm trough attached to a guidepost arm that articulates with a swivel. This assembly supports the weight of the forearm and arm against gravity and is used primarily in patients with high-level tetraplegia or severe proximal arm weakness or paralysis. It may be attached to a wheelchair or table; patients may be able to perform tabletop activities. Prerequisites for its use include a power source, such as neck or trunk muscles (to shift the trunk center of gravity) or adequate scapular movement. A limitation of the BFO is that it does not allow for shoulder flexion, shoulder abduction, or shoulder scapular plane movement.

Upper-extremity splints can be considered remedial or compensatory. In conditions whereby there is a reasonable expectation of recovery, splints can be used to substitute for lost function or protect against malpositioning and contracture until recovery occurs. For those conditions with a more guarded prognosis, splinting may help to substitute for lost function and be used on a more continual basis to augment function. Splinting design classifications include the following :

• 1.
  

  Static splints place the anatomic structures at a nonmoveable maximally available length to enact soft tissue lengthening or a mobilizing effect. It can also be used to position a joint at a comfortable/stable angle for the stabilization of a joint to allow for improved function. Static splints may also be used to redirect forces from poorly moving joints to more efficiently moving joints to augment function or torque transmission.

  
  
• 2.
  

  Serial static splints require the serial remolding of a static splint to progressively increase the mobilization of tight and contracted structures. Serial static splinting techniques are effective in mobilization of tight and contracted joints.

  
  
• 3.
  

  Static progressive splints allow for a patient-controlled application of nonelastic mobilizing force and are used to illicit increased range of motion. It uses the stress-relaxation principal, which is how less force is required to maintain a tissue at a set length over time. Controlled, graded amounts of force are held at maximal tolerable tissue limits.

  
  
• 4.
  

  Dynamic splints use dynamic forces to either elicit increased range of motion or to substitute for lost function. For a mobilizing effect, dynamic splints use the creep principle. This principle describes the ability of a tissue to elongate over time when a constant load is applied to it with the use of elastic components.

  
  
• 5.
  

  Dropout splints allow motion in one direction while blocking motion in another. For example, a splint may be designed to enhance wrist extension while blocking wrist flexion.

Splinting considerations can include patient cognitive status and developmental level, patient acceptance and willingness to wear a splint, skin integrity, weight, cosmetic appearance, and the gadget tolerance of patients or caregivers. Splints can be custom fabricated from low-temperature thermoplastic or neoprene or foam of varying thicknesses or they can be purchased prefabricated.