Review of upper limb kinematics after cervical spinal cord injury: Implications for rehabilitation

Abstract

The aim of this literature review is to provide a clear understanding of motor control and kinematic changes during open-chain upper limb (UL) movements after tetraplegia. Using data from MEDLINE between 1966 and August 2014, we investigated kinematic UL studies after tetraplegia. We included fourteen control case and three series case studies with a total of 161 SCI participants and 126 healthy control participants. SCI participants efficiently perform a broad range of tasks with their UL This is achieved by effective scapulothoracic and glenohumeral compensation which provide a dynamic mechanical coupling between the shoulder and elbow joints thus palliating elbow extension despite triceps brachii paralysis. The mechanism is incomplete, however, since C5-C6 SCI individuals are forced to reduce overhead workspace to keep the elbow extended and to maintain the mechanical dynamic interaction between the shoulder and elbow. Furthermore, motion slowing is a clear kinematic characteristic, caused by: – decreased strength; – triceps brachii paralysis disrupting normal agonist-antagonist co-contraction; – accuracy requirements at movement endpoint; – grasping. Grasping requires a prolonged deceleration phase during transport to ensure hand placement with respect to the to-be-grasped object then wrist extension during grasping to elicit either whole hand or lateral grip. Contrary to the normal pattern, where grasping is prepared during the transport phase, SCI individuals transport the wrist in flexion leading to passive finger opening that did not attest a grip preparation particularly if object size is greater than maximal grip aperture. The pattern (wrist flexed then extended) indicates that reaching and grasping are performed consecutively suggesting that these two phases are independent. Elbow extension restoration causes increased elbow stiffness resulting in increased movement velocity, reduced need for glenohumeral compensation, and overall improved motor control. Rehabilitation and surgical restoration should take these kinematic characteristics into account to reinforce proximal and distal compensations allowing elbow extension and grasp using tenodesis and consequently favoring greater autonomy of individuals after SCI.