The effect of task symmetry on bimanual reach-to-grasp movements after cervical spinal cord injury

Abstract

Injury to the cervical spinal cord results in deficits in bimanual control, reducing functional independence and quality of life. Despite this, little research has investigated the control strategies which underpin bimanual arm/hand movements following cervical spinal cord injury (cSCI). Using kinematics and surface electromyography this study explored how task symmetry affects bimanual control, in patients with an acute cSCI (< 6 m post injury), as they performed naturalistic bimanual reach-to-grasp actions (to objects at 50% and 70% of their maximal reach distance), and how this differs compared to uninjured age-matched controls. Twelve adults with a cSCI (mean age 69.25 years), with lesions at C3–C8, categorized by the American Spinal Injury Impairment Scale (AIS) at C or D and 12 uninjured age-matched controls (AMC) (mean age 69.29 years) were recruited. Participants with a cSCI produced reach-to-grasp actions which took longer, were slower, less smooth and had longer deceleration phases than AMC (p < 0.05). Participants with a cSCI were less synchronous than AMC at peak velocity and just prior to object pick up (p < 0.05), but both groups ended the movement in a synchronous fashion. Peak muscle activity occurred just prior to object pick up for both groups. While there seems to be a greater reliance on the deceleration phase of the movement, we observed minimal disruption of the more impaired limb on the less impaired limb and no additional effects of task symmetry on bimanual control. Further research is needed to determine how to take advantage of this retained bimanual control in therapy.Electronic supplementary materialThe online version of this article (10.1007/s00221-018-5354-8) contains supplementary material, which is available to authorized users.

Properties of the surface electromyogram following traumatic spinal cord injury: a scoping review

“…Another noteworthy application is the study of compensatory movement strategies, which can be accompanied by the development of new muscle synergies [ 68 – 72 ]. Studies have commonly focused on these issues in the context of locomotion [ 3 , 27 , 34 , 35 , 73 – 98 ], while fewer studies focused on reach-to-grasp [ 99 – 107 ], and posture and balance [ 108 – 112 ].…”

Overt visual attention and between-limb asynchrony for bimanual reaching movements

“…Finally, the visual control of bimanual movements is critical to normal everyday functioning and a major challenge for people who have impairments affecting their limb movements and/or vision. While previous studies have carefully investigated bimanual reaching movements in a range of different disorders, such as stroke (Jackson et al 2000;Punt et al 2005aPunt et al , 2005b), Parkinson's Disease (Castiello and Bennett 1997;Alberts et al 1998), and spinal cord injury (Britten et al 2018), we are not aware of any previous clinial studies that have investigated related visual control (i.e., eye movements) in these populations. Examining the visual control of bimanual movements in these populations, using approaches such as the one reported here would be informative and potentially allow coherent planning of rehabilitation strategies.…”