Williams, MJ, Gibson, N, Sorbie, GG, Ugbolue, UC, Brouner, J, and Easton, C. Activation of the gluteus maximus during performance of the back squat, split squat, and barbell hip thrust and the relationship with maximal sprinting. J Strength Cond Res 35(1): 16–24, 2021—The purpose of this research was to compare muscle activation of the gluteus maximus and ground reaction force between the barbell hip thrust, back squat, and split squat and to determine the relationship between these outcomes and vertical and horizontal forces during maximal sprinting. Twelve, male, team sport athletes (age, 25.0 ± 4.0 years; stature, 184.1 ± 6.0 cm; body mass, 82.2 ± 7.9 kg) performed separate movements of the 3 strength exercises at a load equivalent to their individual 3 repetition maximum. The ground reaction force was measured using force plates and the electromyography (EMG) activity of the upper and lower gluteus maximus and was recorded in each leg and expressed as percentage of the maximum voluntary isometric contraction (MVIC). Subjects then completed a single sprint on a nonmotorized treadmill for the assessment of maximal velocity and horizontal and vertical forces. Although ground reaction force was lower, peak EMG activity in the gluteus maximus was higher in the hip thrust than in the back squat (p = 0.024; 95% confidence interval [CI] = 4–56% MVIC) and split squat (p = 0.016; 95% CI = 6–58% MVIC). Peak sprint velocity correlated with both anterior-posterior horizontal force (r = 0.72) and peak ground reaction force during the barbell hip thrust (r = 0.69) but no other variables. The increased activation of gluteus maximus during the barbell hip thrust and the relationship with maximal running speed suggests that this movement may be optimal for training this muscle group in comparison to the back squat and split squat.

The purpose of this multi-study was to assess what impact the closure and reopening of golf courses had on: personal competence; sense of belonging; enjoyment; self-esteem; self-confidence; resilience; social connections; wellbeing and life satisfaction (hereafter referred to collectively as “key variables of interest”) during the COVID-19 pandemic. Golfers (Study 1: n = 298, Study 2: n = 124) ≥16 years old residing in the UK participated in this study which collected data using online surveys. Study 1 was conducted during a period of quarantine restrictions (4–12th May 2020), whilst study 2 took place following the easing of the COVID-19 quarantine restrictions (6–14th July 2020). Within study 1 and study 2, key variables of interest levels were also collected to investigate the association with golf related activities. The findings of study 1 highlighted that negligible and non-significant correlations were observed between golf physical and sedentary activities and key variables of interest (r < 0.3, p > 0.05) except sense of belonging and sedentary golf activities (r = 0.178, p = 0.003). Study 2 highlighted that sense of belonging, enjoyment and wellbeing were significantly associated with outdoor golf course activity (r = 0.186–0.252, p ≤ 0.05). Furthermore, when comparing study 1 and study 2, sense of belonging and life satisfaction significantly improved (p < 0.05, d = 0.2). Based on these findings, playing golf on outdoor golf courses appears to be positively related to sense of belonging, enjoyment and wellbeing. Also, with the reopening of golf courses life satisfaction improved which, together, highlights the beneficial impact that outdoor golf can impart.

The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips.

Electromyography systems are widely used within the field of scientific and clinical practices. The reliability of these systems are paramount when conducting research. The reliability of Myon 320 Surface Electromyography System is yet to be determined. This study aims to determine the intra-session and inter-day reliability of the Myon 320 Surface Electromyography System. Muscle activity from fifteen participants was measured at the anterior deltoid muscle during a bilateral front raise exercise, the vastus lateralis muscle during a squat exercise and the extensor carpi radialis brevis (ECRB) muscle during an isometric handgrip task. Intra-session and inter-day reliability was calculated by intraclass correlation coefficient, standard error of measurement and coefficient of variation (CV). The normalized root mean squared (RMS) surface electromyographic signals produced good intra-session and inter-day testing intraclass correlation coefficient values (range: 0.63–0.97) together with low standard error of measurement (range: 1.49–2.32) and CV (range: 95% Confidence Interval = 0.36–12.71) measures for the dynamic-and-isometric contractions. The findings indicate that the Myon 320 Surface Electromyography System produces good to fair reliability when examining intra-session and inter-day reliability. Findings of the study provide evidence of the reliability of electromyography between trials which is essential during clinical testing.