A significant number of resistance training injuries occur at the shoulder complex. However, there is a lack of research identifying predictive variables, which may increase the risk of these injuries. Certain exercises, such as those requiring the apprehension position (glenohumeral abduction with external rotation), have been investigated and found to be associated with shoulder pain and injury. However, there are additional exercises or positions that may also be associated with increased injury risk. The position of end-range glenohumeral extension, particularly as it pertains to a dip, is a vulnerable position that may have previously been overlooked.

The purpose of this study was to profile and compare the kinematics, using 3D motion capture, and muscle activation patterns, using surface electromyography (sEMG), of three common dip variations; the bench, bar, and ring dips. Thirteen experienced males performed four repetitions of each dip variation. For each participant, repetitions 2–4 were time-normalized and then averaged to produce a mean value for all kinematic and sEMG variables. The mean maximal joint angles and mean peak sEMG amplitudes were compared between each variation using a one-way ANOVA with repeated measures. Several significant differences (p < 0.05) between dip variations were observed in both kinematic and sEMG data. The bench dip predominantly targets the triceps brachii but requires greater shoulder extension range. The mean peak triceps brachii activation was 0.83 ± 0.34 mV on the bench, 1.04 ± 0.27 mV on the bar, and 1.05 ± 0.40 mV on the ring. The bar dip is an appropriate progression from the bench dip due to the higher peak muscle activations. The ring dip had similar peak activations to the bar dip, with three muscles increasing their activation intensities further. These findings have implications for practitioners prescribing the dip, particularly to exercisers with a history of shoulder pain and injury.

The purpose of this study was to profile and compare the bar dip’s kinematics and muscle activation patterns in non-fatigued and fatigued conditions. Fifteen healthy males completed one set of bar dips to exhaustion. Upper limb and trunk kinematics, using 3D motion capture, and muscle activation intensities of nine muscles, using surface electromyography, were recorded. The average kinematics and muscle activations of repetitions 2–4 were considered the non-fatigued condition, and the average of the final three repetitions was considered the fatigued condition. Paired t-tests were used to compare kinematics and muscle activation between conditions. Fatigue caused a significant increase in repetition duration (p < 0.001) and shifted the bottom position to a significantly earlier percentage of the repetition (p < 0.001). There were no significant changes in the peak joint angles measured. However, there were significant changes in body position at the top of the movement. Fatigue also caused an increase in peak activation amplitude in two agonist muscles (pectoralis major [p < 0.001], triceps brachii [p < 0.001]), and three stabilizer muscles. For practitioners prescribing the bar dip, fatigue did not cause drastic alterations in movement technique and appears to target pectoralis major and triceps brachii effectively.

Surfboard paddling is an essential activity when surfing. Research investigating surfboard paddling, especially as it pertains to neuromechanical control and techniques used, is limited. Previous research made use of swim ergometers to examine surfboard paddling demands. The validity of using swim ergometers in surfboard paddling research and training deserves further analysis. To establish ecologically valid findings, researchers have begun to use swim flumes and still-water paddling environments to investigate paddling efficiency and technique. This emerging body of research has reported that muscle activation patterns, intensities, and timings differ as surfers move through different paddle stroke phases. A deeper understanding of paddling's neuromechanical control may help enhance the understanding of how to improve paddle performance and perhaps reduce injury risk. Therefore, the purpose of this review was to identify the gaps in the existing literature to help identify future research directions in relation to surfboard paddling techniques and neuromechanical control.