Retraining High Level Mobility After Brain Injury

Dimensions of Mobility

• Understanding the difference between unidimensional and multidimensional demands for mobility.
• Importance of task-specific resistance training.
• Difference between strength and power and their importance in gait and high-level mobility.

High Level Mobility

• Refers to individuals who can walk independently but struggle with activities they performed before their injury.
• Necessary for return to work, sport, social leisure, and sporting activities.

Patient Goals vs. Rehab Service Provision

• Patient goals often differ from typical rehab service provision.
• Example: A young man who was run over, taking nine months to take his first steps independently, might still not feel recovered until he can play soccer again.

Frameworks and Guidelines

• American College of Sports Medicine guidelines for resistance training.
• Framework for biomechanics-driven exercise prescription.
• Shaki's paper on running across a range of speeds.

Mobility Continuum

• Unidimensional presentation: bed mobility, transfers, standing, walking, stairs, running.
• Outcome measures vary along the continuum: Mobility Scale for Acute Stroke, FIM, Timed Up and Go, HIMAT, Illinois Agility Test.
• Multidimensional aspects: Cognitive, upper limb tasks, crossing the road, different surfaces, lighting conditions, avoiding collisions.

HIMAT (High Level Mobility Assessment Tool)

• Developed to quantify high-level mobility.
• Aids in benchmarking progress.
• Hierarchy: Helps determine the next most difficult goal.
• Example: Stair ascent/descent is less difficult than running.

Why High Level Mobility

• Most people run on most days, even if just a few steps.
• Inability to run significantly impairs mobility.
• Running is a gateway to social, leisure, and sporting activities.
• Positive impact on self-esteem and emotional well-being.

Brain Injury and Recovery

• Significant improvement can occur between two to five years post-injury.
• Recovery can be slow and take many years.
• Majority of brain injuries result from road trauma.

Return to Work

• Lynch's study (2009) in Scandinavia: Working-age stroke survivors who could run a few steps were nearly three times more likely to return to work.

Task Specificity

• Role of the muscle, type of contraction (concentric, eccentric, isometric), speed of contraction, range of motion, groups of muscles, energy systems, intensity/volume.
• Cadence and stride length determine running/walking speed.
• Many patients have lower cadence and unequal step length.

Differences Between Walking and Running

• Flight phase (single support, no support).
• Greater stride length, stride frequency, and proportion of swing phase in running.
• Stable trunk is essential for running.
• Pelvis should be still to allow arm and leg movement.

Spatial Temporal Parameters

• Optimal step length/stride length for everyone.
• Faster leg movement increases running speed.
• Barriers: Spasticity and paresis.

Biomechanics

• Hip: Similar biomechanics in walking and running.
• Knee: Flexion-extension pattern; values about double in running.
• Ankle: Plantar flexion/dorsiflexion.
• Pelvic Rotation: More rotation in walking than running.

Angular Velocities

• As walking speed increases, joints need to move more quickly.
• Requires fast exercises, ballistic plyometric exercises.

Power Events

• Hip extensors: Accelerate body over foot.
• Plantar flexion: Calf generates about 60% of power for forward propulsion.
• Hip flexors: Help swing the leg through.
• Knee: Absorbs power.

Running Program

• Patients must be able to walk independently.
• Advanced gait skills and pre-running skills are taught.
• Introduction of a flight phase.
• Running re-education to improve control, symmetry, and speed.
• Task breakdown for specific activities (e.g., tennis, soccer).

Attributes for Gait and Running

• Stability in stance.
• Adequate clearance in swing.
• Adequate step lengths.
• Appropriate prepositioning of the foot in swing.
• Energy efficiency and smooth transition.

Contributing Impairments

• Strength, balance, contracture, spasticity, motor control.
• Spasticity is less important than originally thought.
• Strength (paresis) is key to change.
• Ankle strength and motor skill are key determinants of recovery.

Muscle Groups

• Hip extensor, hip flexor, and ankle plantar flexor power generation.
• Quads are important but don't contribute to forward propulsion.

Exercise Prescription

• Target the right muscles in the right way.
• Calf muscle: Plantar flexion occurs in 150 milliseconds.
• Consider power training, ballistic training, plyometric training.

Achilles Tendon

• Acts like a spring; stores and releases energy quickly.

• Muscle activity is mostly isometric.
  Examples of Exercises

• Leg sled, Pilates reformer instead of calf raises.

Claw Exercise

• Quick hip knee flexion extension for running.

Transitioning to Running

• Restrict stride length; focus on moving legs quickly.
• Prioritize stride frequency over stride length for safety.
• Focus on core stability and trunk control.
• Hip joint has to do more work as running speed increases.

Core exercises

• Key for stability during leg movement, focus on keeping the body during exercise.

Outcome Measures

• Rivermead Mobility Index, HIMAT, Illinois Agility Test.
• Consider the unique and multidimensional demands of mobility.
• Be specific in improving physical capacity before adding functional tasks.
• Task-specific resistance training is key.