Differences in Core Muscle Electromyographic Activity during Unilateral and Bilateral Carries

Strength and conditioning programs often utilize carriage exercises to challenge postural stability with the intent of improving abdominal muscle endurance and grip-strength. This study examined differences in electromyography (EMG) within core musculature during bilateral and unilateral carries of different loads based on body weight (BW). Thirty-two healthy male, Division III collegiate athletes (age = 19.54 ± 1.06 years, height = 178.62 ± 5.58 cm, weight = 83.11 ± 13.27 kg) completed three different types of carriage holds including a bilateral (BL), contralateral (CL) and ipsilateral (IL) hold using two different weights: 12.5% BW and 25% BW in random order. Unilateral EMG was recorded for the dominant-handed rectus abdominis (RA), external oblique (EO), and erector spinae (ES) muscles. For all three muscles recorded, there were statistically significant two way interactions between the weight held and carry type. All carry types demonstrated greater EMG activity in the RA, EO, and ES during 25% BW compared to 12.5% BW carries. When comparing carry type, CL carries elicited significantly greater EMG activity for all muscles compared to BL and IL carries for both 25% BW and 12.5% BW. Unilateral carries produce much greater EMG activity in opposing abdominal musculature compared to BL carries.