Shoulder Electromyography (Emg) Evaluation During Latissimus-Dorsi Pulldown Variations Following an Accelerated Shoulder Resistance Training Program

Author(s): Musa Lewis Mathunjwa, Megan Ellor, Nduduzo Shandu, Ina Shaw, Gudani Goodman Mukoma, Loyiso Maqina Senzelwe Mazibuko and Brandon Stuwart Shaw.

Background: The latissimus dorsi-pulldown exercise is used to strengthen the elbow flexors, shoulder adductors, and shoulder horizontal adductors. Evidence indicates that resistance training injuries commonly occur in the shoulder complex. Objectives: The purpose of this study was to determine peak muscle activation and time to peak activation using shoulder surface electromyography (sEMG) during latissimus-dorsi pulldown variations following an accelerated shoulder resistance training program. Methods: Thirteen males aged 18 to 35 years participated in the study. The participants completed a five-week, three times weekly supervised intervention program for 60 minutes. The intervention program consisted of a standardized rotator cuff impingement rehabilitation protocol and shoulder stabilizing muscle exercises. Each session commenced with a five-minute arm ergometer warm-up performed at 50 watts with 50-70 revolutions per minute (RPM), followed by five minutes of static upper body musculature. Participants performed three sets of eight to 12 repetitions of floor calisthenics exercises at 50-70% maximal voluntary contraction (MVC) and four sets of 25 repetitions of TheraBand exercises. Each session was concluded with stretching for three sets, with each stretch held for 45 seconds. Results: Peak muscle activation of the middle trapezius significantly improved during wide grip anterior (WGA) (p=0.042). Further, the intervention significantly reduced the time to peak activation of the latissimus-dorsi during WGA (p=0.000) and supinated close grip (SCG) (p=0.000). Time to peak activation also significantly reduced of the middle trapezius during WGA (p=0.010). Similarly, time to peak activation of the triceps long head significantly reduced during WGA (p=0.002), wide grip posterior (WGP) (p=0.045) and SCG (p=0.008). Further, this study demonstrated a significant difference using WGA in the latissimus-dorsi at pre-test, in the lower trapezius using WGP at pre- and post-test, in the middle trapezius using WGA during post-test and using VBG during pre-test and in the triceps long head using WGA at pre- and post-test. Conclusion: This study’s findings are essential in shoulder prevention and rehabilitation programs since the various grips of latissimus dorsi-pulldown exercises are varied in their ability to target specific muscles in the shoulder complex that may need focused attention.