Study On The Effect Of Closed Chain Movements On The Scapular Muscle Balance

Objectives: This study selected SD population and healthy population,using three closed chain movements: push up plus,sitting forward pull and supine pull up,to explore: 1.The difference of activation degree and activation rate of scapular muscles in SD group and healthy group when completing each closed chain movement;2.The difference of activation degree and activation rate of scapular muscles in SD group and healthy group when completing different movements.Methods: 24 subjects with SD on the handedness side were recruited as the experience group and 24 subjects without SD as the control group.The maximum voluntary isometric contraction of UT,MT,LT and SA of scapular muscles was measured by s EMG.The muscle activation of the subjects when they completed three closed chain movements was measured.The activation degree of UT,MT,LT,SA and the activation ratio of UT/ MT,UT/ LT,UT/SA were calculated during each movement.Results: Compared with the control group,the experience group shows:(1)during the process of push up plus,there were significant difference in the activation degree of UT,(p<0.05);there were very significant difference in the activation degree of SA,(p<0.01),there were no significant difference in the activation ratio of UT/ MT,UT/LT,UT/SA.(2)during the process of sitting forward pull,there was significant difference in the activation degree of MT,(p < 0.05);there was no significant difference in the activation ratio of UT/ MT,UT/ LT,UT/SA.(3)during the process of supine pull up,there was a significant difference in the activation of SA,(p <0.05);there was a significant difference in the activation ratio of UT/SA,(p < 0.05).Comparing with the different movements:(1)in the SD group,there was a significant difference in the activation degree of SA between supine pull up and sitting forward pull,(p < 0.05);there was a significant difference in the activation ratio of UT/ SA,(p< 0.05).There was a significant difference in the activation ratio of UT/ LT between supine pull up and push up plus(p < 0.05).(2)in the healthy people group,there was a significant difference in the activation degree of LT between supine pull up and push up plus,(p < 0.05);there was no significant difference in the activation ratio of UT/ MT,UT/ LT,UT/SA.Conclusion:(1)Compared with the healthy people,push-up plus is a better movement to activate the serratus anterior for the people with scapular dyskinesis; sitting forward pull is a better movement to activate the middle trapezius for the people with scapular dyskinesis;supine pull up is a better movement to activate the serratus anterior for the people with scapular dyskinesis and produce the optimal activation ratio of the upper trapezius to the serratus anterior.(2)The patients with scapular dyskinesis can achieve good scapular muscle balance when they complete push up plus,sitting forward pull and supine pull up,in which supine pull up can activate the serratus anterior more efficiently than sitting forward pull and produce a more suitable ratio of upper trapezius and serratus anterior,and supine pull up can produce more suitable ratio of upper trapezius and lower trapezius than push up plus.(3)The healthy people can achieve good scapular muscle balance when they complete push up plus,sitting forward pull and supine pull up,in which supine pull up can activate the lower trapezius more efficiently than push up plus.