Chris Low

A comparison of economy and sagittal plane trunk movements among back-, back/front- and head-loading

Abstract It has been suggested that freedom of movement in the trunk could influence load carriage economy. This study aimed to compare the economy and sagittal plane trunk movements associated with three load carriage methods that constrain posture differently. Eighteen females walked at 3 km.h−1 with loads of 0, 3, 6, 9, 12, 15 and 20 kg carried on the back, back/front and head. Load carriage economy was assessed using the Extra Load Index (ELI). Change in sagittal plane trunk forward lean and trunk angle excursion from unloaded to loaded walking were assessed. Results show no difference in economy between methods (p = .483), despite differences in the change in trunk forward lean (p = .001) and trunk angle excursion (p = .021) from unloaded to loaded walking. We conclude that economy is not different among the three methods of load carriage, despite significant differences in sagittal plane trunk movements. Practitioner summary: This article shows, based on mean data, that there is no difference in economy among back, back/front and head-loading, despite differences in trunk movement. It is possible a combination of factors align to influence individual economy, rather than a single set of factors, applicable to all individuals for each method.

Attributes that determine the success of a field hockey drag flick: a coach's perspective

Achilles tendon injuries frequently occur among athletes who partake in activities and sports containing running. Specifically, it is reported that achilles tendinopathy affects 38% of males and 26% of female elite tennis players (Montalvan et al., 2004, Journal of Medicine of Science and Tennis, 4, 14–15). This type of injury is associated with restricted subtalar joint mobility and limited ankle dorsiflexion. Therefore, in order to avoid negatively impacting training and performance, as well as optimising prevention strategies and appropriately managing Achilles tendinopathy in elite tennis players is of paramount importance. The central aim of this study was to critically review the literature to determine clear training considerations when working with players suffering from achilles tendinopathy. A comprehensive search strategy was employed using relevant electronic databases PubMed, Medline, PEDro, ScienceDirect and SportDiscuss. In addition, reference lists were hand searched for potentially relevant research. All studies were identified using study inclusion and exclusion criteria. Results from the selected studies were directly transferred and critically appraised. Findings highlighted a number of training considerations that optimise performance of tennis players who have ongoing achilles tendinopathy. These were tendon unloading patterns, such as cross conditioning (Davenport et al., 2005, Physical Therapy, 85(10) 1093–1103); eccentric training of the gastrocnemius group (Cook and Purdham, 2003, Clinical Sports Medicine, 22, 777–789); and dynamic tendon lengthening exercises (Alfresdon and Cook, 2007, British Journal of Sports Medicine, 41, 211–216). These management strategies may be beneficial for strength and conditioning coaches to incorporate as part of optimal conditioning for tennis players. This can be by periodising these methods into a tennis season with the aim of preventing achilles tendinopathy, or by utilising these exercises within rehabilitation sessions for players already experiencing this problem. Future studies comparing specific tennis-conditioning approaches could provide valuable insight into the possible contributing risk factors to achilles and patellar tendinopathy in tennis players.