Restoring Upright Mobility After Spinal Cord Injury

Restoring Upright Mobility After Spinal Cord Injury Using Functional Electrical Stimulation

Up to 15 able-bodied individuals will participate in one testing session to evaluate the effectiveness of the A-FES system. Up to 20 individuals with SCI will participate in 12 sessions of A-FES therapy. At each session, participants will stand on a force plate (Accu Sway, AMTI, USA) with the A-FES system (Compex Motion II, Compex Motion, Switzerland) donned. The centre of pressure (COP) will be calculated in real time using the force plate data. The calculated COP will be presented to participants on a monitor and they will be instructed to shift their COP in the indicated directions as represented by a cursor (i.e. training with visual feedback). The intensity of electrical stimulation provided by the A-FES system will be regulated by the measured COP in a closed-loop manner. In this study we propose to develop and evaluate the clinically-feasible A-FES system for the training of standing balance.

Inclusion Criteria:

1. A traumatic or non-traumatic, non-progressive (AIS) C or D SCI;
2. ≥18 years old;
3. Able to stand independently for 60s;
4. Moderate level of trunk control as evidenced by the ability to reach forward >2 inches in standing (i.e. score of 2 on the BBS Reaching Forward task50,51); and
5. Free of any other condition besides SCI that significantly affects walking or balance (e.g., no vestibular disorder, significant vision loss, stroke).

Exclusion Criteria:

1. Severe spasticity in the legs;
2. Contractures in the lower extremities that prevent achieving a neutral hip and ankle position, or extended knee;
3. A prior lower extremity fragility fracture;
4. An injection of botulinum toxin to leg muscles in the past six months;
5. Peripheral nerve damage in the legs (i.e. leg muscles unresponsive to electrical stimulation);
6. A pressure sore (>grade 2) on the pelvis or trunk where the safety harness is applied; o
7. Contraindications for FES52 (i.e. implanted electronic device, active cancer or radiation in past 6 months, epilepsy, skin rash/wound at a potential electrode site).

Participants will be withdrawn from the study if FES irritates their skin.