For those with limited upper limb function due to conditions like spinal cord injury, stroke, muscular dystrophy, or other neuromuscular disorders, mobile arm supports (MAS), also known as Deltoid Aides, provide crucial assistance in improving independence, participation in daily activitie, and opportunities to strengthen and use their arms. These mechanical devices help compensate for weakened shoulder and arm muscles, allowing users to perform tasks they might otherwise be unable to do.
The MAS functions by reducing gravitational resistance, allowing individuals with weak proximal upper limb muscles—particularly the deltoid and biceps—to engage in controlled movements. The MAS facilitates neuromuscular re-education and task-specific training, helping individuals develop motor control while reducing compensatory movements. This tool can be a game changer.
The device consists of a series of linkages, springs, or pulleys that counteract the weight of the arm, thereby enhancing active range of motion. By offloading the arm's weight, the MAS permits smoother, more efficient movement and decreases the effort required for tasks such as feeding, grooming, and accessing electronic devices.
🔬 What the Science Says
Research supports the use of MAS in improving functional reach, endurance, and engagement in daily tasks. A study by Atkins et al. found that 100% of individuals with C4–C5 tetraplegia who used an MAS were able to perform at least one functional task they otherwise could not, such as eating, brushing teeth, driving a power wheelchair, writing, or playing board games. Moreover, 92% of therapists indicated they would prescribe MAS to motivated individuals with very weak (2-/5) biceps and deltoid muscles.¹
The study also highlighted the challenges and limitations of MAS, including increased wheelchair width, setup complexity, and frequent adjustments required for optimal function. Despite these drawbacks, however, MAS remains a valuable tool in rehabilitation, with newer models offering improved adjustability and usability.
🎯 Diagnoses That May Benefit from MAS
Spinal cord injury (SCI) (C4–C5 tetraplegia)
Guillain-Barré syndrome
Amyotrophic lateral sclerosis (ALS)
Spinal muscular atrophy (SMA)
Duchenne muscular dystrophy (DMD)
Peripheral neuropathy
Post-stroke hemiparesis with proximal weakness
➡️ Methods and Techniques
Positioning and Setup: Proper alignment is key for effective use—making sure that the support facilitates smooth, functional movement without impeding other activities.
Task-Specific Training: Integrating MAS into therapy sessions with functional tasks (e.g., self-feeding, writing, or reaching for objects) optimizes motor learning and engagement.
Strengthening: This tool can be a great opportunity to strengthen their arm in gravity-minimized positions. let them explore the movement they have while positioning the device appropriately to optimize their range (and resistance if appropriate).
Gradual Progression: Some patients may start with full mechanical assistance and gradually transition to increased independent movement as strength and motor control improve.
💡 The Therapist’s Role
Assessment: Evaluate upper limb strength, endurance, range of motion, and coordination to determine the appropriateness of MAS.
Customization: Adjust the MAS to fit the individual’s body mechanics, therapeutic goals, and environmental needs.
Training and Education: Guide patients in proper use, ensuring they understand how to integrate MAS into daily routines.
Monitoring and Adjustment: Regularly reassess effectiveness, making modifications based on patient progress and feedback.
🚧 Common Challenges and Solutions
Cost Barriers: MAS devices can be expensive, limiting accessibility for many individuals. Solution: Seek funding options through insurance, grants, or nonprofit organizations. Additionally, reaching out to manufacturers may provide opportunities for trials or discounted pricing.
Environmental Barriers: Some MAS systems are bulky or restrictive in certain settings. Solution: Consider table- or wheelchair-mounted versions instead of free-standing ones.
Lack of Engagement: Users may feel discouraged if immediate results aren’t seen. Solution: Incorporate motivational strategies and goal-setting to improve adherence.
📊 Assessments & Measurements
Functional Independence Measures (FIM): Track improvements in daily task performance.
Range of Motion & Strength Testing: Evaluate any physical gains achieved with MAS support.
Patient Satisfaction Surveys: Gain insight into usability, comfort, and overall effectiveness.
🌀 My Take
As a young OT, I neglected the benefits of the mobile arm support because it was clunky and time-consuming to set up. As a “seasoned” clinician, I’ve come to pull it out more and more. Psychologically it gives patients a degree of freedom with their BUE that they don’t get otherwise. Physically, it allows versatility and plenty of opportunity for movement in low arc ranges which means that patients get their reps in. And functionally, it can be the difference between someone feeding themself or driving their power wheelchair and relying on a caregiver to do it.
References
Atkins, M. S., Baumgarten, J. M., Yasuda, Y. L., Adkins, R., Waters, R. L., Leung, P., & Requejo, P. "Mobile Arm Supports: Evidence-Based Benefits and Criteria for Use." PMCID: PMC2582429.