Article

Altered neuromuscular control due to compromised joint position sense
may contribute to recurrent shoulder instability.
The purpose of the
present study was to examine whether individuals with anterior shoulder
instability exhibit larger shoulder position sense errors than those with healthy
shoulders in both passive matching and active positioning. DESIGN: This was a
between-groups study with repeated measures. METHODS: Ten people with anterior
shoulder instability and 15 people with healthy shoulders participated in the
study. Shoulder position sense was examined with 3 different protocols (passive
motion to remembered shoulder rotation angles and active shoulder abduction and
rotation to verbally specified positions) in positions of both mid-range and
end-range of motion. RESULTS: Participants with unstable shoulders exhibited
significantly larger errors (by 1.8 degrees on average) in perception of shoulder
position compared with those with healthy shoulders during passive matching.
During active positioning, participants with unstable shoulders were able to
voluntarily move the shoulder to verbally specified angles as accurately as those
with healthy shoulders in both abduction (0.85 degrees difference) and rotation
(0.99 degrees difference) tasks. CONCLUSIONS: Results of this study indicate that
people with unstable shoulders can perceive shoulder angles as accurately as
people with healthy shoulders in activities with voluntary arm movements.
Compared with passive matching, better information from muscle spindles and other
sources during voluntary arm movements may compensate for the potential joint
position sense deficits after the injury. Therefore, individuals with an unstable
shoulder may have adequate neuromuscular control to engage proper protective
mechanisms to stabilize the shoulder joint during functional activities.

Langue : ANGLAIS