Improved kinematics of unrestrained arm raising in C5–C6 tetraplegic subjects after deltoid-to-triceps transfer

Abstract

Study design: Prospective comparative study. Objective: To determine whether control of upper limb joint synergy during unrestrained arm raising involving shoulder and elbow flexion is modified by deltoid-to-triceps transfer. Setting: Rehabilitation unit for spinal cord injury patients, France. Methods: Five C6 subjects with C5-C6 tetraplegia sustained posterior deltoid-to-triceps transfer and were compared to a control group of 11 subjects. Kinematics of shoulder and elbow joints before, 6 month and 1 year after surgery, during straight-arm raising (SAR) in the plane of the scapula and hand-to-nape-of-neck movements (HNNMs) were explored. Motion was recorded with a six-camera Vicon motion analysis system and the data used to assess the coupling of elbow and shoulder flexion velocities (EFVs and SFVs) and extension velocities. Results: All subjects were initially assessed at 6.9 months (mean) postsurgery. Three of the upper limbs were assessed a second time (mean 17.9 months). The first assessment showed an increase in shoulder flexion amplitudes in tetraplegic subjects with presurgery shoulder flexion deficits. Peak SFVs and EFVs and extension velocities were slightly modified at the first postsurgery assessment and dramatically improved at the second assessment during both SAR and HNNM. Despite these increased velocities, joint coordination was only partially restored. Conclusion: A restored elbow active extension improves the speed of elbow flexion. The additional improvement of shoulder motion emphasises the relation between joints in the control of arm movement.

Analysis of tetraplegic reaching in their 3D workspace following posterior deltoid-triceps tendon transfer

“…Generalised analysis across groups seems to mask the individuality of patients' responses and adaptation to surgery. As this study established the workspace in which tetraplegic patients can reach and the ability of tetraplegics to reach to this workspace, this study coupled with data from functional tasks 9 and movement control 6 has provided a greater understanding of the functional benefits of the tendon transfer. Future studies using EMG within the workspace would allow researchers to examine how the central nervous system adapts to the tendon transfer and activates the upper-limb muscles to reach effectively.…”

“…Reaches at these heights should be considered when undertaking assessment of tetraplegic participants clinically or experimentally in the future. Remy-Neris et al 9 showed the improvement in co-ordination shown by post-tendon transfer tetraplegics during two arm raising tasks. After 16 months, the tetraplegic participants in their study had comparable range of motion and angular velocity to healthy control participants.…”

“…11 Previous studies suggest that after tendon transfer tetraplegics can co-ordinate their arms similarly to healthy individuals but this has only been shown during two functional tasks 9 or toward targets placed on a table. 6,7 Analysis of reaching within an individual's 3D workspace would allow tetraplegic patients' unconstrained reaching ability to be fully and objectively evaluated.…”

“…9 Although such tasks provide insight into altered movement control strategies and functional capabilities, the change in reachable workspace is unknown. Reachable workspace describes the volume within which an individual can reach and it is important in the objective assessment and rehabilitation of patients with upper-limb pathology.…”

How do C6/C7 tetraplegic patients grasp balls of different sizes and weights? Impact of surgical musculo-tendinous transfers

“…These results corroborate clinical observations of the functional benefits of surgical restoration of active elbow extension by musculo-tendinous transfer. 8,13,24,30 Current hypotheses concerning the benefit of the presence of an active elbow extensor include the ability to maintain a stable arm posture, especially when the hand is raised above the shoulder level, as is the case in the present task, 31 the ability to interact with a variety of external objects and forces, 32 or the ability to propulse a manual wheelchair. In addition, our results suggest that the presence of a non-paralysed triceps, or of a surgically transferred muscle, facilitates prehension, probably by stabilisation of the elbow during the transport of the objects.…”