Adaptive Sport Participation Following T7-T8 Paraplegia


Ella Xu
BME 5990, Rehabilitation Engineering
May 8, 2026

Case

  • 27F with T7-T8 complete paraplegia from ski racing accident 3 years ago
  • Structure/Function: bilateral lower extremity paralysis, neurogenic bladder/bowel, secondary risks (atrophy, osteoporosis, pressure injury)
  • Activity: manual WC user, independent in ADLs, unable to perform lower-extremity dependent activities
  • Participation: restricted from sport and recreation central to her identity
  • Goal: return to adaptive mountain biking and alpine skiing
  • Stakeholders: husband, RE team + clinicians, insurance, manufacturers, Vermont Adaptive Ski and Sports

RE Team

Role Contribution
Engineer Device selection, optimization
Physical Therapist Biomechanical assessment (TCT, ROM)
Occupational Therapist Home / environment usability
Urologist Neurogenic bladder/bowel management
Adaptive Sports Coach Training program, sport-specific goals
Insurance Provider Financial feasibility
Device Mfg Technical specs, customization

Candidate Solutions (restoration)

FES (Functional Electrical Stimulation)

  • Electrical impulses via surface/implanted electrodes → contracts paralyzed lower extremity muscles
  • Modality: FES-assisted cycling
  • Benefits neuroplasticity, counters atrophy and bone density loss

ESS (Epidural Spinal Stimulation)

  • Surgically implanted electrode array on posterior spinal cord
  • Bypasses damaged neural pathways, enables user to regain voluntary motor function
  • High cost, surgical risk, tuning parameters require extensive trial-and-error
ESS FES

M. Bellman, "Epidural Stimulation vs. FES," Myolyn, Aug. 2024.

Candidate solutions (replacement)

ReWalk Exoskeleton

  • powered lower limb exoskeleton with motorized hip and knee joints
  • Enables independent ambulation with forearm crutches

aMTB (Adaptive Mountain Bike)

  • Recumbent hand-cycle for off-road terrain
  • Upper extremity propulsion, no lower extremity function required
  • Directly targets user's sport participation goal
aMTB

Source: Oregon Adaptive Sports

FES ESS WC (ref) ReWalk aMTB
Sport goal alignment + 0 0 − +
Independence + + 0 0 +
Terrain versatility 0 + 0 + +
Donning/doffing ease 0 + 0 − +
Maintenance burden 0 − 0 − 0
Insurance likelihood 0 − 0 + −
Financial cost − − 0 − −
Metabolic cost + + 0 − 0
Learning curve − − 0 − 0
Total +2 +1 0 −3 +3

Optimization: aMTB

Parameters: seat angle, handlebar/crank position

Inputs:

  • Trunk Control Test (TCT) score → seat recline
  • Upper extremity joint ROM → handlebar position

Digital Twin:

  • Models user geometry, trunk stability, joint ROM
  • Simulates trail features (bumps, grades, turns)
  • Optimizes parameters before physical fitting

On-bike sensors: heart rate monitor, power meter, accelerometer, IMUs

Assessment Plan

Domain Test Threshold
Capacity 6-min ride test ≥10% more distance vs. generic setup
Performance Timed trail segment (Strava) ≥10% faster, zero falls
Participation Structured interview (week 8) ≥60 min/week, positive enjoyment

LLM Comparison

ChatGPT recommends: FES, (followed by trunk orthosis, aMTB)

  • Reasoning: broader long-term benefits beyond sport (bone density, cardiovascular, bladder)
  • Assessment protocol: VO2 max, bone density scan, power output; measured at different points in time

Would I change my solution?
aMTB addresses SPP goals, FES promotes GPP; they are complementary.