Upper limb kinematics after cervical spinal cord injury: a review

Journal of NeuroEngineering and Rehabilitation, 2015 · DOI: 10.1186/1743-0003-12-9 · Published: January 30, 2015

Spinal Cord Injury Neurology Biomechanics

Simple Explanation

This review examines how people with cervical spinal cord injuries (SCI) perform upper limb movements like reaching and grasping. It looks at how their movements differ from those of people without SCI. After a spinal cord injury, people can still perform a broad range of tasks. This review found that individuals with SCI still plan and execute movements with precision, maintaining accuracy and efficiency. Individuals with SCI show patterns of shoulder and elbow coordination similar to healthy individuals during reaching and reach-to-grasp. The main change occurs at the scapulothoracic joint, where scapula rotation increases during reaching.

Study Duration

1966 to December 2014

Participants

164 SCI participants and 131 healthy control participants

Evidence Level

Not specified

Key Findings

1
Elbow extension without the triceps relies on increased shoulder movements, creating a dynamic link between shoulder and elbow function.
2
Reaching and grasping become separate actions after SCI, unlike typical movements where grasping is prepared during reaching.
3
Movements are slower after tetraplegia, potentially due to muscle weakness, disrupted muscle coordination, the need to maintain accuracy, or reliance on tenodesis.

Research Summary

SCI participants efficiently execute a broad range of upper limb tasks. Kinematic evidence shows that, even after SCI, movements are planned and executed according to strong kinematic invariants like movement endpoint accuracy and minimal cost. Elbow extension with a weak or paralyzed triceps brachii relies on increased movements of the scapulothoracic and glenohumeral joints. This provides a dynamic coupling between the shoulder and elbow which palliates the triceps brachii paralysis but limits the superior maximal reach. One main kinematic characteristic after tetraplegia is motor slowing attested by increased MT which can be a direct consequence of the strength deficit or due to a behavioral adaptation in order to preserve the accuracy of the movement and ensure grasping by tenodesis.

Practical Implications

Rehabilitation Strategies

Targeting specific compensatory mechanisms (scapulothoracic and glenohumeral joint movement) can improve upper limb function.

Surgical Interventions

Restoring elbow extension can improve kinematics and reduce compensatory movements.

Assistive Technologies

Devices that assist with grasping or provide elbow extension torque can improve movement speed and accuracy.

Study Limitations

1
Variability in SCI level and completeness of injury across studies.
2
Differences in experimental setups and kinematic measurement systems.
3
Limited number of studies examining specific movement types (e.g., fast elbow flexion).

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