Sports Related Injury Mechanism on Ice Hockey Skills: A System Review

As one of the official sports in the Winter Olympics Games, ice hockey is a competitive team activity combining changeable skating skills with agile hockey skills. The biomechanical studies of different skills used by ice hockey players are considered to be effective ways to improve performance and reduce injury risks. The purpose of this study was to conduct a review that elucidated the biomechanical research about those techniques. Englishlanguage literature searches of the electronic databases in Google Scholar, Web of Science, and ScienceDirect were performed from 1999 to June 2019, using the following key words: ‘Biomechanics’ AND ‘Ice hockey player’ OR ‘Ice hockey athlete.’ Of the 455 identified articles, 17 studies met the inclusion criteria and were included in this review. Most of the studies were conducted by Canadians and it is consistent with the country’s dominant position in ice hockey competitions. Forward skating, skating start, and shooting were the most studied skills in order to optimize sports performance and reduce injury risks. Players with different levels or sex would exhibit different biomechanical characteristics during forward skating and skating start, and those characteristics may also alter with each stride. In addition, several factors, including the players and sticks’ characteristics, may be associated with the shot accuracy. While ice hockey is always considered as a high-risk sport, little biomechanical studies have been conducted to explore the injury mechanisms and preventions of specific ice hockey techniques. Future research on the biomechanical analysis of ice hockey players’ skills, especially the injuries during some specific ice hockey skills, is much needed.

Biomechanics of the Diabetic Foot

The lower extremity is uniquely equipped to withstand the demands of ambulation that involve a complex orchestration of events to efficiently propel the body forward. The reparative properties and functional capabilities are compromised in the diabetic foot and ankle. Therefore, the diabetic foot is at risk for the development of a chronic ulcer or necessitates the need for an amputation. Unique forces are experienced in the lower extremity during ambulation. Specifically, sagittal and shear forces are less tolerated in the diabetic foot. This chapter discusses the normal and abnormal biomechanics of the diabetic foot and ankle that lead to the development of an ulcer and promote its chronicity. Further, a biomechanical-focused conservative and surgical approach to prevention, treatment, and methods to curtail recidivism will be addressed. This review contains 7 figures, 3 tables, and 42 references. Key Words: biomechanics, diabetic foot ulcer, foot deformity, function, offloading, plantar pressure, recidivism, shear

Delta Efficiency of Uphill Roller Skiing With the Double Pole and Diagonal Stride Techniques

Delta efficiencies for uphill roller skiing with the double pole (DP) and diagonal stride (DS) techniques were determined among 4 female and 4 male cross-country ski racers in order to examine for differences between techniques and between the sexes. Each skier roller-skied on a motorized ski-treadmill at 1.7% and 7.1% grades with both techniques at 2 to 4 different speeds. Steady-state oxygen uptake values were used to calculate the differences in metabolic requirements for roller skiing at the 2 grades (ΔE). The differences in external work rates between the 2 grades (ΔW) were calculated from the work rates for overcoming rolling resistance and elevating the transported mass against gravity. Delta efficiencies (ΔW/ΔE) ranged from 14 to 36%, were significantly greater (p < 0.001) for DS than DP, and showed a significant (p < 0.01) velocity effect for DS. Delta efficiencies were 27% greater (p < 0.05) for the women compared with the men for DP, and significant (p < 0.05) correlations were found between efficiency for DP and body mass. This suggests that the higher efficiency with DP for female skiers is at least partially due to their lower body mass. Key words: biomechanics, cross-country skiing, mechanical power, mechanical energy cost