Objectives: To analyze shoulder muscle activation when performing push-ups under different stability conditions and heights.

Study design: Comparative study by repeated measures.

Setting: Valencia University laboratory.

Participants: 29 healthy males participated.

Main outcome measures: Subjects performed 3 push-ups each with their hands at 2 different heights (10 vs. 65 cm) under stable conditions and using a suspension device. Push-up speed was controlled and the testing order was randomized. The average amplitudes of the electromyographic root mean square of the long head of the triceps brachii (TRICEP), upper trapezius (TRAPS), anterior deltoid (DELT) and clavicular pectoralis (PEC) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC).

Results: Suspended push-ups at 10 cm resulted in greater activation in the TRICEP (17.14 +/- 1.31 %MVIC vs. 37.03 +/- 1.80 %MVIC) and TRAPS (5.83 +/- 0.58 %MVIC vs. 14.69 +/- 1.91 %MVIC) than those performed on the floor. For DELT and PEC similar or higher activation was found performing the push-ups on the floor, respectively. Height determines different muscle activation patterns.

Conclusions: Stable push-ups elicit similar PEC and higher DELT muscle activation, being greater at 10 cm; whereas suspended push-ups elicit greater TRAPS and TRICEP muscle activation, being greater at 65 cm.