HUMAN PERFORMANCE LABORATORY Practical Applications AN ELECTROMYOGRAPHIC COMPARISON OF A MODIFIED PULL-UP WITH AND WITHOUT A SUSPENSION DEVICE Emily V. Witte, B.S., Ronald L. Snarr, B.S., CSCS, Christopher T. Jenkins, B.S., Robert M. Brannan, and Michael R. Esco, Ph.D, CSCS*D. Human Performance Lab, Auburn University at Montgomery, Montgomery, AL HUMAN PERFORMANCE LABORATORY Abstract Introduction Methods, cont. Results, cont. The use of suspension devices for performing traditional exercises is a relatively new method of training that utilizes novel equipment designed to challenge stability. There is very limited research available to determine if such training influences muscular activation patterns compared to traditional exercise. The standard pull-up is an exercise that targets a large portion of the upper body, but is challenging for some individuals. This movement can be modified by placing the lower limbs on a stable, supportive surface underneath the body while performing the pulling movement. Purpose: The purpose of this study was to compare the electromyographic (EMG) activity of the middle trapezius (MT), latissimus dorsi (LD), posterior deltoid (PD), and biceps brachii (BB) during a modified pull-up (PU) versus a modified suspension pull-up (SPU). Methods: Fifteen healthy men (n = 11, ages 26.82 ± 4.02 years) and women (n = 4, ages 22.25 ± 0.96 years) participated in the study. All participants completed 4 repetitions of the PU and SPU. Mean peak EMG values were recorded and used for data analysis for each muscle group. Results: The PU demonstrated values of: MT = 2.53 ± 1.33, PD = 2.67 ± 1.24, LD = 3.49 ± 2.07, BB = 4.69 ± 1.76. The SPU elicited values of: MT = 2.35 ± 1.34, PD = 2.72 ± 1.12, LD = 3.44 ± 1.92, BB = 4.48 ± 1.71. The results indicated that there were no significant differences between PU and SPU (p > 0.05) in EMG activity of each tested muscle. Conclusions: This study showed no significant difference in muscle activity for the measured muscle groups (MT, PD, LD, and BB) when performing a modified pull-up with and without a suspension device. Further study is warranted to determine muscle activation values in smaller stabilizing muscles while performing the PU and SPU. Practical Applications: Practitioners should note that there are no measurable differences in muscle activation when performing a PU compared to a SPU. Therefore, a suspension device may be used in place of traditional stable equipment to elicit similar muscular activation levels in the MT, PD, LD, and BB while performing a modified pull-up. New methods are constantly being introduced in an attempt to improve upon traditional means of resistance training. One such method includes the use of suspension devices, which are designed to challenge stability while performing traditional exercises. However, limited research is available to determine the muscular activation patterns associated with suspension training when compared to those of traditional exercises. The standard pull-up is a common exercise that targets a large portion of the upper body. This exercise can be performed both traditionally as well as with the use of suspension devices. However, non-assisted pull-ups can be challenging for some individuals. Therefore, to accommodate those individuals, this movement can be simply modified by placing the lower limbs on a stable, supportive surface underneath the body in order to reduce the amount of work performed while executing the pulling movement. Electrode Placement Biopac surface EMG electrodes were used in this investigation along with Acqknowledge software to analyze peak EMG activation. All electrodes were placed on the right side of the body and in direct line with the muscle fibers. Latissimus Dorsi electrodes were placed approximately 4 cm beneath the inferior tip of the scapula, half the distance between the lateral border of the torso and the spine, spaced 2 cm apart and at an oblique angle (25o) following the muscle fibers. Posterior deltoid electrodes were placed 2 cm below the lateral border of the spine of the scapula, spaced 2 cm apart and angled toward the deltoid tuberosity. Middle trapezius electrodes were placed 2 cm apart and parallel to the muscle fibers between the thoracic vertebrae and the medial aspect of the spine of the scapula. Electrodes for the biceps brachii were placed vertically 2 cm apart directly over the muscle belly on the anterior aspect of the upper arm. A ground electrode was placed over the right anterior superior iliac spine (ASIS). Table 2: Mean EMG values (mV)   PU SPU MT 2.53 ± 1.33 2.35 ± 1.34 PD 2.67 ± 1.24 2.72 ± 1.12 LD 3.49 ± 2.07 3.44 ± 1.92 BB 4.69 ± 1.76 4.48 ± 1.71 Conclusions This study showed no significant differences in EMG muscle activation across any of the muscle groups (MT, PD, LD, and BB) when performing a modified pull-up with and without a suspension device. This may be due to the increased stability provided by the floor during the modified pull-up. Further study is warranted to determine muscular activation in smaller stabilization muscles while performing the PU and SPU. Purpose The purpose of this study was to compare the electromyographic (EMG) activity of the middle trapezius (MT), latissimus dorsi (LD), posterior deltoid (PD), and biceps brachii (BB) during a modified pull-up (PU) versus a modified suspension pull-up (SPU). Statistical Analysis All peak EMG activations were recorded and averaged over the four repetitions performed for each exercise. A sample T-Test was used to determine if there were differences in raw (mV) values between the two exercises. A prior statistical significance was set to a value of p < 0.05. Practical Applications Practitioners should note that there are no measurable differences in muscle activation when performing a PU compared to a SPU. Therefore, a suspension device may be used in place of traditional stable equipment to elicit similar muscular activation levels in the MT, PD, LD, and BB while performing a modified pull-up. Methods Participants Fifteen subjects (11 men and 4 women) volunteered to participate in this investigation. Mean ages for men and women were 26.82 ± 4.02 and 22.25± 0.98, respectively. Before participation, subjects completed a health history questionnaire and informed consent. Participants chosen for this study were free from cardiovascular, pulmonary, musculoskeletal disorders, and had no neurological impairments. Any subject with previous shoulder, arm, or back injuries were excluded from the study. All participants were required to perform 4 repetitions of the PU and SPU in a randomized order. Descriptive statistics for the subjects are provided in Table 1. References 1. Youdas, JW, Amundson, CL, Cicero, KS, Hahn, JJ, Harezlak, DT, and Hollman, JH. Surface electromyographic activation patterns and elbow joint motion during a pull-up, chin-up, or PERFECT-PULLUP™ rotational exercise. J Strength Cond Res 24(12):3404-3414, 2010. 2. Snyder, BJ, and Leech, JR. Voluntary increase in latissimus dorsi muscle activity during the lat pull-down following expert instruction. J Strength Cond Res 23(8):2204-2209, 2009. 3. Sperandei, S, Barros, MAP, Silveira-Junior, PCS, and Oliveira, CG. Electromyographic analysis of three different types of lat pull-down. J Strength Cond Res 23(7):2033-2038, 2009. 4. Signorile, JF, Zink, AJ, and Szwed, SP. A comparative electromyographical investigation of muscle utilization patterns using various hand positions during the lat pull-down. J Strength Cond Res 16(4):539-546, 2002. Table 1: Descriptive characteristics   MALES FEMALES ALL AGE 26.55 ± 4.18 22.25 ± 0.96 25.40 ± 4.07 HEIGHT (cm) 178.82 ± 8.59 173.75 ± 5.68 177.47 ± 8.06 WEIGHT (kg) 82 ± 7.95 68 ± 7.57 78.27 ± 9.92 BMI 25.66 ± 2.08 22.50 ± 2.01 24.82 ± 2.46 Body Fat % 10.37 ± 0.05 21.12 ± 0.04 13.24 ± 0.07 Results The PU demonstrated values of: MT = 2.53 ± 1.33, PD = 2.67 ± 1.24, LD = 3.49 ± 2.07, BB = 4.69 ± 1.76. The SPU elicited values of: MT = 2.35 ± 1.34, PD = 2.72 ± 1.12, LD = 3.44 ± 1.92, BB = 4.48 ± 1.71. The results indicated that there were no significant differences between PU and SPU (p > 0.05) in EMG activity of each muscle tested (Table 2). This presentation was funded by the Student Government Association and Research Council at Auburn University Montgomery