The Comparison of Scapular Position in Dominant and Non-Dominant Limbs of Girls with and without Hyperkyphosis Abnormality

Scapula plays an important role in producing smooth and coordinated
movement of shoulder girdle. Also, a change in natural scapula position has a direct
relationship with some postural abnormalities. Since in dominant limb, there are
differences in the ways of environmental nerves such as higher sensory detection
threshold, the conduction speed as well as side differences in muscles, the aim of
the present study was to compare scapula position (protraction and upward
rotation) in dominant and non-dominant sides of female university students with
and without hyperkyphosis abnormality. The study method was descriptive and
comparative. Subjects were selected by non-random method and they had no
history of sport, pain and injury in their shoulder and spine. Then, using Iranian
thoracic kyphosis degree norm, subjects were divided into two groups of
hyperkyphosis and normal kyphosis (mean age 21±1.05, 21.1±1.32 yr respectively).
Scapula protraction and upward rotation degree were calculated using Divta
method. The results showed no significant difference in protraction and scapula
upward rotation between dominant and non-dominant sides of normal kyphosis
group (p=0.09, p=0.19) whereas in hyperkyphosis group, there was a significant
difference between thoracic kyphosis degree and the distance of the two scapulas
(r=0.37). Also, in this group, a significant difference was observed in scapula
protraction between dominant and non-dominant sides (p=0.001). Although there
was no significant difference in protraction and scapula upward rotation between
dominant and non-dominant sides of normal kyphosis group, these values were
higher in dominant side while scapula protraction was significantly higher in
1 - Corresponding – Author : Tel : 09155710676, Email : s_cheshmi@bandargaziuu.ir
Journal of Faculty of Physical Education, University of Tehran 7
dominant side of hyperkyphosis group. Therefore, dominant hand might be
responsible for some degrees of asymmetry of scapula position and the dominant
side is more influenced by the hyperkyphosis deformity. It is recommended that in
corrective exercise programs, more attention be paid to muscle imbalance in
dominant limb to treat hyperkyphosis deformity. Also, normal subjects must
perform the exercises to prevent scapula asymmetry and to create muscle balance
in dominant limb.