Upper body push to pull ratios in law enforcement officer recruits.

BACKGROUND: Law enforcement recruits (LER) often encounter shoulder injuries, which may cause attrition from academies. Investigating required upper body muscular fitness may inform of muscular balance around shoulder joints through anterior and posterior ratios in LER. OBJECTIVE: To investigate push to pull ratios (P2P) and factors related with P2P in LER. METHODS: LER (95 males; 12 females) completed testing during a single session in the academy's first week: body mass, one-repetition maximum (1RM) bench press, push-up repetitions (reps) to failure, and pull-up reps to failure. Calculations were: estimated pull-up 1RM=body mass+0.033*(body mass x pull-ups); endurance P2P (eP2P)=push-ups / pull-ups; strength P2P (sP2P)=bench press 1RM / estimated pull-up 1RM. Pearson correlation coefficients assessed relationships among tests and P2P (p < 0.05). RESULTS: The sP2P was positively correlated with bench press 1RM and push-ups. The eP2P was negatively associated with pull-up reps and 1RM. Females had similar eP2P, but lower sP2P than male recruits (p < 0.05). CONCLUSION: Practitioners may benefit from examining eP2P and sP2P as they should not be used interchangeably. Future research should examine whether the P2P ratios are associated with injury and subsequent inability to successfully complete law enforcement training academies.

Unintended Changes in Contralateral Limb as a Result of Acute Gait Modification.

Gait modification using real-time biofeedback is a conservative intervention associated with positive outcomes. Results from systematic reviews corroborate the effectiveness of various strategies employing real-time biofeedback for reducing estimated knee joint load. The effects on the nonmodified limb, however, remain unclear. Biomechanical changes to the nonmodified limb were investigated during unilaterally implemented medial knee thrust, lateral trunk lean, and toe-in foot progression. Nineteen healthy participants were recruited. Ten trials were completed for each gait condition including baseline. Assigned magnitude for each gait modification strategy was individualized based on the mean and SD of the gait parameter during baseline. Visual real-time biofeedback was provided. During medial knee thrust, participants' nonmodified limb presented with increased: first peak medial knee contact force, internal first peak knee extensor moment, as well as knee- and hip-flexion angles at internal first peak knee extensor moment. Observed biomechanical changes are elucidative of the body's attempt to attenuate increased external loads. These findings may carry significant implications for pathological populations. Load redistribution to the nonmodified side may result in unfavorable long-term outcomes particularly in patients with bilateral diagnosis. Future studies should explore acute and chronic changes in the nonmodified limb of individuals with knee osteoarthritis.