Electromyographical Comparison of a Traditional, Suspension Device, and Towel Pull-Up

Comparison of Muscle Activity During a Ring Muscle Up and a Bar Muscle Up

The muscle up (MU) is a variation of a common gymnastics movement that combines a pull up and a dip. It can be performed on a bar (BMU) or a set of rings (RMU). The difference in upper extremity muscle recruitment (MR) between BMU and RMU has not been evaluated. Therefore, the purpose of this study was to compare the MR of select muscles during BMU and RMU. Ten active males (27.6 ± 7.9 years) performed 5 repetitions of BMU and RMU in randomized order. Muscle recruitment of the upper (UT) and lower trapezius (LT), serratus anterior (SA), pectoralis major (PM), latissimus dorsi (LD), triceps brachii (TB), biceps brachii (BB), and forearm flexors (FF) was assessed using electromyography. A 2 × 2 ANOVA (ring vs bar, pull phase vs push phase) with repeated measures was performed for each muscle. Least significant differences post hoc tests were performed when a significant interaction effect occurred. The RMU significantly elicited more muscle activation in the UT (p = 0.007), BB (p = 0.001), and FF (p = 0.001) during the pull phase. The RMU also significantly elicited more muscle activation in the TB (p = 0.025) and BB (p = 0.001) during the push phase. These results suggest that the instability of the RMU primarily increases the required recruitment of the upper limbs but does not significantly change the recruitment of the shoulder stabilizers. Appropriate upper limb development is needed to perform the RMU and the BMU may be a better technique to learn first due to its lower difficulty.

Effect of the Pronated Pull-Up Grip Width on Performance and Power-Force-Velocity Profile

Purpose: The objective of this study was to investigate the influence of the grip width on the power-force-velocity-profile, the maximal strength, and performance during a repetition to failure test in the pull-up exercise (PU). Method: Fourteen trained males performed an incremental loading and repetitions to failure test with the PU exercise using biacromial and free grip widths. Power-force-velocity relationship, 1RM, and repetitions completed were determined. Results: The mean grip width used by participants was 20.04% higher in the free grip width condition (p < .001). There were similar results in the 1RM (p = .954), repetitions to failure test (p = .117), and power-force-velocity profile (p > .05) in both grip width conditions. A stronger relationship was observed between 1RM and repetitions to failure test during the biacromial (R² = 0.720; p < .001) with respect to the free grip width (R² = 0.607; p = .002). Conclusion: Therefore, the choice of a free or a biacromial grip width does not affect the maximal strength, power-force-velocity relationship, nor the repetitions to failure during the PU exercise.

Upper body strength endurance evaluation: A comparison between the handgrip strength and three body weight tests

BACKGROUND: The hand-grip strength test has been widely adopted to evaluate upper limb strength. Other field based tests as push-ups and pull-ups are commonly used for the same purpose. It is however unclear if these may be used interchangeably for upper body strength evaluation. OBJECTIVE: The purpose of this investigation was to evaluate strength endurance of the upper body and understand which test could be the most appropriate for upper body evaluation. METHODS: Thirty-eight healthy young male participants were tested with three tests comprised of: 1) push-ups (PS), 2) pull-ups (PL) and 3) parallel dips (PD) performed to exhaustion. Grip strength (GS), total number of repetitions, time-to-complete the test, repetition cadence and rate of perceived exertion (RPE) were also retrieved for investigation. RESULTS: Repetitions, time-to-complete the test and repetition cadence significantly differed across the three tests (p< 0.001). No difference in the RPE was present. No correlation was present between GS and the other tests. No correlation was present between RPE and performance values and time-to-complete the tests. BMI was positively correlated to RPE in all tests. All tests strongly correlate to each other (PS vs. PL r= 0.55; PS vs. PD r= 0.64; PL vs. PD r= 0.70) and to time-to-complete the test (PS r= 0.79; PL r= 0.69; PD r= 0.66). Only the results of the PD correlate to their respective repetition cadence (r= 0.66). CONCLUSIONS: GS is not suitable to evaluate strength endurance. PS, PL and PD are all suitable to evaluate strength endurance. However, PD may be preferred to evaluate the upper body, if velocity also needs to be taken into account.

Differences in the Electromyographic Activity of Lower-Body Muscles in Hip Thrust Variations

Collazo García, CL, Rueda, J, Suárez Luginick, B, Navarro, E. Differences in the electromyographic activity of lower-body muscles in hip thrust variations. J Strength Cond Res 34(9): 2449-2455, 2020-Coaches often use variations of an exercise to train a specific muscle. The purpose of this study was to analyze motor patterns in 4 variations of one of the most popular strength training exercises for the lower body: the barbell hip thrust. Seven experienced personal trainers performed a series of 8 repetitions of each variation with a load of 40% one repetition maximum. Subjects rested 3' between series. Electromyographic (EMG) muscle activity was measured in the rectus femoris, vastus medialis; vastus lateralis; gluteus maximus; gluteus medius; biceps femoris; and semitendinosus. Variations of the hip thrust exercise were performed by changing the position of the feet (feet were moving away from the body) and the direction of force exerted by subjects (intentional force aimed at hip's external rotation and knee's flexion). Repeated-measures analysis of variance revealed significant differences in EMG in all muscles except for the gluteus medius, where no differences were observed among variations. The results obtained suggest that hip thrust variations have different motor patterns, which can be exploited to adapt an exercise to the individual needs of each athlete.

Efficacy of whole-body suspension training on enhancing functional movement abilities following a supervised or home-based training program

BACKGROUND

The purpose of this study was to determine the effects of suspension training on functional movement and body composition, and to compare the effectiveness of home-based training to supervised training.

METHODS

Seventeen healthy subjects (8 males, 9 females, age=21.8±3.4 y) with no recent history of resistance training were randomly assigned to a home-based or supervised training group. Subjects performed an 8-week suspension training program consisting of 10 exercises targeting major muscle groups, twice per week for the duration of the study. Pre- and post-intervention testing included body composition using air displacement plethysmography, and a functional movement screen (FMS) to measure functional movement abilities.

RESULTS

The 8-week training program significantly improved total FMS scores across the whole sample of subjects (Pre=16.4; Post=17.5; P=0.004), with no differences in improvements between groups. When compared separately, only the supervised group significantly improved FMS scores. There was also a significant increase in lean mass across the total sample of subjects (Pre=52.4 kg; Post=53.3 kg; P=0.03) with no differences between groups. But when compared independently, neither group exhibited a significant increase in lean mass.

CONCLUSIONS

When completed as a whole-body exercise program over an 8-week period, suspension training can improve functional ability and increase lean mass in both a supervised and a home-based setting.

Validity and Reliability of Surface Electromyography Measurements from a Wearable Athlete Performance System

The Athos ® wearable system integrates surface electromyography (sEMG ) electrodes into the construction of compression athletic apparel. The Athos system reduces the complexity and increases the portability of collecting EMG data and provides processed data to the end user. The objective of the study was to determine the reliability and validity of Athos as compared with a research grade sEMG system. Twelve healthy subjects performed 7 trials on separate days (1 baseline trial and 6 repeated trials). In each trial subjects wore the wearable sEMG system and had a research grade sEMG system's electrodes placed just distal on the same muscle, as close as possible to the wearable system's electrodes. The muscles tested were the vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF). All testing was done on an isokinetic dynamometer. Baseline testing involved performing isometric 1 repetition maximum tests for the knee extensors and flexors and three repetitions of concentric-concentric knee flexion and extension at MVC for each testing speed: 60, 180, and 300 deg/sec. Repeated trials 2-7 each comprised 9 sets where each set included three repetitions of concentric-concentric knee flexion-extension. Each repeated trial (2-7) comprised one set at each speed and percent MVC (50%, 75%, 100%) combination. The wearable system and research grade sEMG data were processed using the same methods and aligned in time. The amplitude metrics calculated from the sEMG for each repetition were the peak amplitude, sum of the linear envelope, and 95^th percentile. Validity results comprise two main findings. First, there is not a significant effect of system (Athos or research grade system) on the repetition amplitude metrics (95%, peak, or sum). Second, the relationship between torque and sEMG is not significantly different between Athos and the research grade system. For reliability testing, the variation across trials and averaged across speeds was 0.8%, 7.3%, and 0.2% higher for Athos from BF, VL and VM, respectively. Also, using the standard deviation of the MVC normalized repetition amplitude, the research grade system showed 10.7% variability while Athos showed 12%. The wearable technology (Athos) provides sEMG measures that are consistent with controlled, research grade technologies and data collection procedures.