JOURNAL WATCH

THE EFFECT OF PITCHING BIOMECHANICS ON THE UPPER EXTREMITY IN YOUTH AND ADOLESCENT BASEBALL PITCHERS. Davis JT, Limpisvasti O, Fluhme D, Mohr KJ et al. American Journal of Sports Medicine 2009;37:1484–1491.

The background to this study was that increased pitch counts have been linked to increased complaints of shoulder and elbow pain in youth baseball pitchers. To date, however, improper pitching mechanics have not

been shown to adversely affect the upper extremity in youth pitchers. A total of 169 baseball pitchers, aged 9–18 years, were analysed using a quantitative motion analysis system and a high-speed video while throwing fastballs. The correct performance of five common pitching parameters was compared with each pitcher’s age, humeral internal rotation torque, elbow valgus load and calculated pitching efficiency. Results: Motion analysis correlated with video analysis for all five parameters. The pitchers with better pitching mechanics generate lower humeral internal rotation torque, lower elbow valgus load and more efficiency than pitchers with improper mechanics.

sportEX comment

Although this is about baseball pitchers, the premise behind it can be applied to any sport that involves throwing techniques performed at maximal effort. The conclusion of this and many other pieces of research is that proper technique reduces load. Medical personnel need to be working with coaches, especially those coaching lower age groups, to get the message across that proper technique not only improves performance but also may help to prevent injuries.

GENDER DIFFERENCES AND RELIABILITY OF SELECTED PHYSICAL PERFORMANCE TESTS IN YOUNG WOMEN AND MEN. Augustsson SR, Bersås E, Thomas EM, Sahlberg M et al. Advances in Physiotherapy 2009;11:64–70.

The aim of this study was to evaluate the test–retest reliability of sit-ups and push-ups and to determine performance differences in muscular endurance (maximal number of repetitions) and power (timed maximal number of repetitions in 30s) in young women and men. A total of 38 females and 25 males, aged 18–35 years, participated in the study. Results: A high reliability was noted for both the sit-up and the push-up tests (intraclass correlation values ranged from 0.92 to 0.95). There were no significant differences between the men and the women in the mean number of sit-ups (42 and 41 repetitions, respectively, for endurance; 16 and 14 repetitions, respectively, for power), whereas the men performed significantly

more push-ups than the women (39 and 17 repetitions, respectively, for endurance; 29 and 13 repetitions, respectively, for power).

sportEX comment

Push-ups and sit-ups are among the most commonly used body-weight exercises to improve and assess strength and fitness, but to date there is a lack of reproducible test protocols in the scientific literature. This study shows that the tests do have a high reliability and are valid for evaluating muscular endurance and power in both sexes. The fact that men performed twice as many push-ups as women in the 30s timeframe indicates that, when designing programmes for women, attention should be turned towards strengthening training exercises of the upper body.

TOPICAL RUBEFACIENTS FOR ACUTE AND CHRONIC PAIN IN ADULTS. Matthews P, Derry S, Moore RA, McQuay HJ. Cochrane Database of Systematic Reviews 2009;(3):CD007403

Definition: a rebefacient is a substance for external application that produces redness of the skin.

A search of the major databases found six placebo-controlled trials and one active controlled clinical trial for acute pain, and seven placebo- and two active controlled trials for chronic pain, regarding the use of topical salicylates. Outcomes were reported at 3–10 days for the acute conditions and 7–14 days for the chronic conditions. Results: The authors found no difference between topical rubefacient and topical control. There were insufficient data to draw conclusions with active controls. In the chronic conditions, the efficacy of salicylates compares poorly with that of topical non-steroidal anti-inflammatory drugs (NSAIDs).

sportEX comment A lot of these substances are

used in sport, but here’s the rub (pun intended): overall, the results don’t support their use. The big question is: where there were positive results, was this due to the product or the mechanical and/or the psychological effect of the rubbing?

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sportEX dynamics 2009;22(Oct):4-6