Variability and Reliability of Punching Impact Kinetics in Untrained Participants and Experienced Boxers

Abstract

Lenetsky, S, Brughelli, M, Nates, RJ, Cross, MR, and Lormier, AV. Variability and reliability of punching impact kinetics in untrained participants and experienced boxers. J Strength Cond Res 32(7): 1838-1842, 2017-Striking impact kinetics are central to performance in combat sports. Despite a multitude of assessment, few in the literature have explored the variability and reliability of punching force assessment. Consequently, this study assessed the variability and reliability of measured punching impact kinetics in untrained and experienced boxers using a recently developed and validated method of striking dynamometry. Intrasession (both cohorts) and intersession (untrained only) measures of impulse, peak, and mean force were determined across 4 punch types (jabs, crosses, lead, and rear hand hooks) using coefficient of variation (CV), intraclass correlation coefficients (ICCs), and typical error of measurement (TEM). Moderate (ICC <0.67 or CV >10%) to small (ICC >0.67 and CV <10%) variability was found for intrasession results of both groups, the majority having small variability. Intersession findings of the untrained cohort had a similar spread of variability, but with the majority exhibiting moderate variability. All variables except for mean force of the cross in the experienced boxer cohort were found to exhibit a "moderated" magnitude of reliability determined by standardized TEM scores (TEM = 0.60-1.19) during intrasession testing. All variables had moderate reliability during intersession. This method was found to have acceptable variability and reliability when monitoring punching impact kinetics.

Variability of Multiangle Isometric Force-Time Characteristics in Trained Men

“…The ICC and CV were used to explore relative and absolute variability respectively. An ICC<0.67 and CV>10% were deemed as having large variability, moderate variability when either the ICC>0.67 or the CV<10%, but not both, and small variability when ICC>0.67 and CV<10% (12,15). Variability was also examined via TEM to provide the reader with a practical interpretation of the magnitude of error expected for any change in the mean (12,15).…”

“…An ICC<0.67 and CV>10% were deemed as having large variability, moderate variability when either the ICC>0.67 or the CV<10%, but not both, and small variability when ICC>0.67 and CV<10% (12,15). Variability was also examined via TEM to provide the reader with a practical interpretation of the magnitude of error expected for any change in the mean (12,15). Magnitudes for effects were calculated by doubling the TEM result (12, 15) with thresholds of 0.2-0.6 (small), 0.6-1.2 (moderate), 1.2-2.0 (large), 2.0-4.0 (very large) and >4.0 (extremely large) (9,12,15).…”

The reliability of a linear position transducer and commercially available accelerometer to measure punching velocity in junior boxing athletes

“…After a match has ended (if a knock-out is not achieved), both the quality and the quantity of strikes ultimately determined the victor. 1–4 As such, a means of objectively measuring punch quality may provide valuable information for both coaches and athletes during training, competition preparation, and to monitor changes in punch ability over time. In particular, peak punch velocity and power can influence the quality of a punch, and ultimately the impact force applied to an opponent.…”

“…1 Therefore, punching velocity (a contributing factor to overall power) is of considerable importance, 2 and may be a key determinant of successful outcomes in both amateur and elite boxing competitors. 3,4 For example, Smith et al. 5 demonstrated that peak punching power was greatest in elite compared to both intermediate and novice boxers.…”

Biomechanical assessment of various punching techniques

“…Although there is some knowledge regarding punching capabilities in different settings, mostly related to sports and/or martial arts with punch intensity measured by different methods [4][5][6][7][8][9], to our knowledge there is no comprehensive study concentrating on forensic aspects of various kinds of strikes and punches with intraindividual and interindividual comparisons. This study aimed to obtain a data basis enabling to characterize various aspects of punching performance for both the dominant and non-dominant hands, for men and women, and for various kinds of punching techniques for the use in legal medical assessment.…”