Identifying Dysfunctional Movements at the Computer

Many persons with RSI demonstrate dysfunctional movement patterns at the computer which play a strategic role in the pathomechanics of RSI.  The normal position of function for the upper extremity at the keyboard is with the midline of the hand aligned with the midline of the forearm, the wrist in approximately 20 degrees of extension, and the fingers maintaining a natural curve with the metacarpophalangeal flexion of approximately 45-50 degrees.  The thumb should be in line with the radius. 

Dysfunctional movement patterns include working with malaligned joints and applying force inappropriately.  For example, workers will overuse their joints in end-range positions or sustain awkward anatomical relationships.  This distorts  proper length-tension relationships between muscle groups.   With this malalignment, the worker often applies force impulsively through the wrist and fingers, setting himself up for strain and inflammation.

Typical anatomical malalignments implicated in the pathogenesis of RSI include (see insert):

• Extended or abducted thumb;
• Hyperextended MCP, DIP or splayed fingers;
• Excessive finger lifting;
• Ulnar deviation of the wrist or excessive flexion/extension;
• Loss of the carpal arch;
• Forearm/elbow in more than 90 degrees of flexion with excessive pronation;
• Excessive elbow tension;
• Shoulder abduction, scapular protraction and elevation;
• Forward Head Posture, and
• Ribcage depression

Traditional treatments address the myofascial shortening, muscular imbalances, nerve compression, tonal alterations, and postural deviations, as well as correct the ergonomics of the work station.   Clinicians emphasize regaining normal muscle-tendon extensibility, joint mobility, nerve gliding, proprioceptive acuity, and fluid dynamics. 

While traditional rehabilitation modalities of pain relief, stretching, strengthening, and adapting the work station play an important role in restoring tissue health, this does not mean the person can return to work without risk of reinjury.

Regardless of the factors relating to the etiology, the occupational science clinician needs to treat the movement dysfunction.   A differential diagnosis and a list of pathomechanical factors are not enough to establish an adequate treatment plan.  When the dysfunction is learned, maladaptive neuromuscular patterns of motor control are now mapped in the cortex.  The patterns of misuse must be retrained.   The functional patterns of  positions, movements, and activities that affect the clinical signs and symptoms, and the client's awareness of his/her own contribution to the pattern of injury both are  essential in working to redirect the person toward health.