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Grabbing a cup of coffee, hailing a bus, using a computer, holding a phone to your ear, or simply scratching your head… Most of our daily actions involve our arms. But in many situations, when living with a muscular weakness, moving the arm can be challenging or even impossible.
This significantly impacts our ability to engage in daily activities and meaningful occupations, be they within domains of self-care, productivity or leisure. Occupational Therapists (OTs) can benefit from a deeper understanding of upper limb assistive technology and environmental adaption, to maximise potential for occupational engagement.
Various devices exist to assist arm movement, such as arm supports, robotic arms and gripping aids. These devices help people maintain autonomy, by enabling them to manipulate objects for essential home tasks, work, or leisure activities. They also facilitate interaction with others and help keep muscles active.
Causes of reduced arm mobility
Many conditions can lead to loss of arm mobility due to motor or sensory effects, such as neuromuscular disease, or nervous system damage and lesions. Among the neuromuscular pathologies that affect arm mobility, examples include Duchenne Muscular Dystrophy, Infantile Spinal Amyotrophy, Limb-Girdle Muscular Dystrophy, Myotonic Dystrophy type 1, and Charcot-Marie-Tooth disease. In these types of pathologies, the loss of strength can be caused by muscular deterioration at the neuromuscular, nerve or motor neuron junction.
Symptoms vary depending on the individual, the disease and its stage of progression. They can affect different parts of the arm, with:
muscle weakness in the upper part of the arm (proximal muscles)
muscle weakness in the forearm (distal muscles)
impairment in the fingers and hand (fine dexterity, e.g. grip and pinch strength)
In the case of Duchenne muscular dystrophy for example, muscle weakness is functionally apparent earlier in the lower limbs; it becomes more noticeable in the upper limbs following the loss of the ability to walk. Clinical and radiological studies show that motor deficits in these patients first affect the shoulders and progressively reach the muscles of the arms and forearms, especially those acting as extensors of the elbow and wrist. In the case of neuromuscular diseases, the reduction in muscle strength in patients generally leads to a loss of range of motion.
This limitation in movement subsequently causes tendon contractures or osteo-articular stiffness. The resulting pain, which further limits movement and the ability to perform activities, creates a vicious circle.
Lesions or injuries of the central nervous system (such as stroke, traumatic brain injury, cerebral palsy and spinal cord injuries) can lead to highly variable motor deficits in the upper limbs. In the case of a spinal cord injury (SCI), the higher the lesion in the spinal cord, the more the muscles of the upper arm (proximal muscles) will be affected. Depending on the degree of the lesion, the patient will retain more or less arm function. A complete lesion will result in a complete absence of movement below the lesion; an incomplete lesion will allow for arm movement, but with reduced strength.
Patients who have experienced a stroke often display impaired reach and grasp functions. In this case, movements can be slower, less fluid and/or have a shorter range. The difficulty these patients have adapting the force used to grasp, manipulate and release objects appropriately is of a different nature to that presented by individuals with a spinal cord injury or a neuromuscular disease. Hence, many individuals living with a neuromuscular condition or a lesion of the central nervous system can benefit from the use of an assistive device for arm or hand function.
Existing upper limb assistive technology
Five types of assistive devices for the arm and hand are available. These devices assist or perform movements for the user. Each type meets a specific need:
-Mechanical Arm Supports- Suitable where the person can perform the movement, but where repetitive actions cause fatigue.
-Electric Arm Supports- Suitable where lifting the arm is difficult or impossible, but where bending the elbow and shoulder rotation are possible.
-Robotic Arms with Gripping Devices- Suitable where arm and hand movements are severely limited or non-existent.
-Gripping Aids for the Hand- Suitable where it is possible to close the hand, but where maintaining the grip is challenging.
-Electric Meal Aids- Suitable where lifting the hand to the mouth is difficult or impossible.
These devices are adaptable to a variety of joint mobility situations, accommodating different levels in the shoulder, elbow and hand. Several clinical scales have been designed to measure the arm mobility, such as the Brooke Upper Extremity Rating Scale.
Assessment methods for the fitting of an upper limb assistive device
Assessing for the recommendation of an assistive device
For this type of assistive device, there is an increasing tendency to use a top-down approach, starting with the individual's activities, lifestyle habits and preferences. Integrating users' feedback into the recommendation process and adopting an ecological perspective, rather than focusing on physical limitations, helps reduce the abandonment rate of these assistive devices (Hocking, 1999).
-1) Usage-
Assessing needs in terms of particular uses allows for:
Prioritisation: For example, for one patient, using a computer might be more important than eating. These choices will impact the direction of the assistive device.
Gathering indicators for post-fitting assessment, by targeting the most important activities. For example, if an individual wants to use the device for fishing three times a year, the well-being associated with this activity might take precedence over the frequency of use criteria.
→ Clinical scales for evaluating usage: COPM, MOHOST, LIFE-H
-2) Environment-
Here, the specific conditions of the distant environment (flat, hilly, etc.) and the immediate environment (specifics of the wheelchair, etc.) are determined. These elements will affect the functionalities of the assistive device. For example, a person living in a very hilly area will need greater ability to lock their arm support.
→ Environmental assessment tools: Assessment can be multimodal; photos, sketches, videos, tracking movements at home or places of use, etc.
-3) Motor abilities-
These abilities should be related to usage. Even if object manipulation is limited, the ability to take and give an object may be very important. The objective is to assess the arm as a whole:
Potential pain
Possible contractions or joint limitations
Skin issues (possible allergies to contact with materials)
Sensitivity (feeling at different points of support)
Movements (ability to move, manipulate objects, etc)
→ Clinical scales for evaluating motor abilities:-
Functional assessment of the upper limb; Orthopaedic assessment; 400 point assessment; Box and Blocks Test; Jamar: dynamo + pinch; FIM; Minnesota; MFM; Nine Hole Peg Test; Perdue Pegboard Test; Brooke Upper Extremity Rating Scale; CUE-T; Pain (VAS); Barthel ADL Index; Myotools; Nepsy; Ecological situation observations; Preston; PUL; RULM.
This assessment of usage, environment and motor abilities results in the definition of functional specifications. Based on these specifications, the occupational therapist can then match the needs with existing devices on the market.
Assessment of the assistive device - after fitting
The evaluation of the assistive device can occur at various points in time, depending on usage and how the patient is monitored; one week, three months or one year following fitting. This step evaluates the progress in performing activities with the assistive device (as opposed to without), the satisfaction level, or improvement in quality of life.
The 2007 report by the National Authority for Health in France suggests that assessments should take place in environments where the device can be expected to be used. In this way, the device’s effectiveness can be assessed in relation to the individual’s primary activities.
→ Clinical scales for assistive device assessment: QUEST (Demers, 1999), Goal Attainment Scale (GAS) (Krasny Pacini, 2013), COPM, PIADS.
A guidebook to explore this topic further
The best way to learn about upper limb assistive devices is to try them! This allows you to have a sense of how the device works, experience the sensation of assisted arm movement and determine in which situations it may be suitable.
To discover more about upper-limb assistive devices, you can freely download the guidebook 'Assistive Technology for Arm Mobility in Europe' (Orthopus, 2024):
This resource was co-written by healthcare professionals, associations, equipment installers and researchers. It also includes testimonials from the true experts: the users themselves.
Other resources
Global indicators of assistive technology use amongst occupational therapists - Report of WFOT's Global Surveys (World Federation of Occupational Therapists, 2019)
Global report on assistive technology (World Health Organization, 2022)
Clinical scales for upper-limb (Orthopus) - for before and after the fitting
Bergsma, A., Janssen, M.M.H.P., Geurts, A.C.H., Cup, E.H.C. and de Groot, I.J.M. Different profiles of upper limb function in four types of neuromuscular disorders. Neuromuscular Disorders. December 2017; 27 (12): 1115-1122. doi: 10.1016/j.nmd.2017.09.003. Epub 2017 Sep 15. PMID: 29033278.
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