The purpose of this study was to examine the relationships between muscle cross-sectional area (CSA), maximal strength, power output, and maximum potentiation characteristics. The vastus lateralis and biceps femoris CSA, one repetition maximum (1RM) back squat, 1RM concentric-only half-squat (COHS) strength, static jump power output, and maximum potentiation characteristics of 17 resistance-trained men was assessed during several testing sessions. Pearson’s correlation coefficients were used to examine the relationships between CSA, strength, power output, and maximum potentiation measures. Moderate-to-strong relationships existed between CSA and strength measures (r = 0.462–0.643) as well as power output (r = 0.396–0.683). In addition, moderate-to-strong relationships existed between strength and power output (r = 0.407–0.548), while trivial relationships existed between strength and maximum potentiation (r = −0.013–0.149). Finally, small negative relationships existed between CSA and maximum potentiation measures (r = −0.229–−0.239). The results of the current study provide evidence of the interplay between muscle CSA, strength, power, and potentiation. Vastus lateralis and biceps femoris CSA may positively influence an individual’s back squat and COHS maximal strength and squat jump peak power; however, muscle CSA and absolute strength measures may not contribute to an individual’s potentiation capacity. Practitioners may consider implementing resistance training strategies that improve vastus lateralis and biceps femoris size in order to benefit back squat and COHS strength. Furthermore, implementing squatting variations—both full and partial—may benefit jumping performance.

ABSTRACT  Title of dissertation: Analysis and comparasion of squat exercise due to surface EMG  Objectives of dissertation: To measure and describe the structure involving specific muscles durring back squat, front squat and smith machine squat exercise.  Method: Surface EMG analysis and simple kinematic analysis.  Results: Activation of m. gluteus maximus was highest after the start of excentric movement. Main muscle working on the chase between the concentric and excentric movement was m. rectus femoris. Very similar timing and synergy were between m. erector spinae and m. biceps femoris. In this study was not higher activation of m. quadriceps femoris during front squat exercise, activation of m. gluteus maximus were also higher.  Key words: squat, strengthening, bar, front squat, back squat, Smith machine squat, bodybuilding, weightlifting, powerlifting, EMG analysis, kinematic analysis 6