Objective: Firstly, we wanted to look for appropriate closed kinetic chain exercises to restore intramuscular imbalance between upper trapezius (UT) and serratus anterior (SA) in overhead athletes. Secondly, we wanted to determine the influence of using diagonal pattern muscle recruitment during knee push up plus (KPP) exercises on scapular EMG activity.
Design: Single group repeated-measures design.
Setting: Controlled laboratory study.
Participants: Thirty-two physically active individuals in good general health, who did not have a history of neck and/ or shoulder injury or surgery, nor participated in high level overhead sports or performed upper limb strength training for more than 5 hours per week.
Interventions: Subjects performed the standard KPP and 6 variations.
Main outcome measurements: Electromyographic activity of the 3 trapezius parts and the SA.
Results: Four exercises with a low UT/SA can be selected for rehabilitation of intramuscular balance: standard KPP, KPP with homolateral leg extension, KPP with a wobble board and homolateral leg extension, and one handed KPP. The use of a wobble board during KPP exercises and performance on one hand has no influence on SA EMG activity.
Heterolateral leg extension during KPP stimulates LT activity, while homolateral leg extension stimulates SA activity.
Conclusions: In case of intramuscular scapular imbalance, some exercises are preferable over others because of their low UT/SA ratio. The use of a kinetic chain approach during KPP exercises influences scapular muscle activity.