Facilitation of dependent transfers with functional neuromuscular stimulation: a computer simulation study.

Area of Science:

• Biomechanics
• Rehabilitation Engineering
• Neuroscience

Background:

• Spinal cord injury (SCI) often results in paralysis, necessitating caregiver assistance for patient mobility.
• Manual patient transfers pose significant ergonomic risks, particularly to the lower back, for caregivers.
• Functional neuromuscular stimulation (FNS) offers a potential method to reanimate paralyzed muscles.

Purpose of the Study:

• To investigate the biomechanical effects of using FNS to assist vertical patient lifts in individuals with SCI.
• To quantify the reduction in caregiver spinal load when FNS assists with patient transfers.
• To evaluate the feasibility of FNS in reducing caregiver injury risk during dependent transfers.

Main Methods:

• A two-part musculoskeletal modeling and simulation approach was employed.
• Part 1: Simulated vertical lifts of an SCI patient model with and without simulated FNS-induced muscle activation.
• Part 2: Estimated caregiver spinal compression at L5/S1 using a separate caregiver model during simulated lifts.

Main Results:

• Simulations without FNS predicted caregiver spinal compression exceeding 1.3 times the NIOSH recommended 'Action Limit'.
• Simulations incorporating two distinct FNS activation patterns predicted caregiver spinal compressions below NIOSH recommendations.
• FNS significantly reduced the external forces required from the caregiver.

Conclusions:

• FNS-assisted vertical patient lifts can substantially decrease the biomechanical load on caregivers.
• Implementing FNS during patient transfers may significantly lower the risk of musculoskeletal injury for healthcare providers.
• Simulation results support FNS as a viable technology to enhance safety and efficiency in SCI patient care.