Column-editor : James M. Mensch
Tamerah Hunt and Fredrick Gardin
Column-editor : James M. Mensch
Stephen Dobson and Bill Gerrard
Unlike most major U.S. sport teams, it is common for professional soccer clubs around the world to trade players for cash. This article develops a model of the player-transfer market in soccer in which observed transfer fees are determined by player characteristics, selling-club characteristics, buying-club characteristics, and time effects. The model is based on data on 1,350 transfer fees in English professional soccer from June 1990 to August 1996. The estimated model is used to investigate the rate of inflation in transfer fees. In addition, the determination of transfer fees is considered within different segments of the transfer market. It is found that the determination of transfer fees differs markedly among segments.
Simon Wang and Stuart M. McGill
Spine stability is ensured through isometric coactivation of the torso muscles; however, these same muscles are used cyclically to assist ventilation. Our objective was to investigate this apparent paradoxical role (isometric contraction for stability or rhythmic contraction for ventilation) of some selected torso muscles that are involved in both ventilation and support of the spine. Eight, asymptomatic, male subjects provided data on low back moments, motion, muscle activation, and hand force. These data were input to an anatomically detailed, biologically driven model from which spine load and a lumbar spine stability index was obtained. Results revealed that subjects entrained their torso stabilization muscles to breathe during demanding ventilation tasks. Increases in lung volume and back extensor muscle activation coincided with increases in spine stability, whereas declines in spine stability were observed during periods of low lung inflation volume and simultaneously low levels of torso muscle activation. As a case study, aberrant ventilation motor patterns (poor muscle entrainment), seen in one subject, compromised spine stability. Those interested in rehabilitation of patients with lung compromise and concomitant back troubles would be assisted with knowledge of the mechanical links between ventilation during tasks that impose spine loading.
Roberta L. Pohlman and Larry D. Isaacs
This preliminary investigation examined the potential effects of low birth weight on motor performance in children. Seventeen pairs of children were matched by age and placed in one of five age groups (5-9 years). One of each pair weighed 2,200 grams or less at birth (low birth weight, LBW) and the other weighed more than 2,200 grams at birth (normal birth weight, NBW). Three types of data were collected: motor development data, reaction time data, and anthropometric data. Nine paired t tests were performed. To control for alpha level inflation, the Bonferroni technique was employed. The two groups did not differ significantly in present body weight. Tests of gross motor development found the NBW group to be more advanced in both locomotor skills and object control skills. With regard to triceps skinfold, again the NBW group was found to have greater values. No other between-group measurements of body composition were significant. In addition, girls were significantly higher than boys in percent body fat. These preliminary results suggest the LBW children lag behind their NBW peers in the development of the basic fundamental motor skills.
Lauren Anne Lipker, Caitlyn Rae Persinger, Bradley Steven Michalko and Christopher J. Durall
cuff dimensions were not reported. Total inflation time could not be calculated from the study data. The exercises consisted of straight leg raises, hip joint abduction, hip joint adduction, half squats, step-ups, resisted knee flexion with elastic tubing, and knee-bending walking exercises. Subjects
Joshua T. Slysz and Jamie F. Burr
intervention group was accomplished using an automated tourniquet system (Zimmer Automated Tourniquet System 1500 model; Soma Technology Inc, Bloomfield, CT) with periodic inflation to 220 mm Hg. An individual intervention session comprised of 3 cycles of 4-minute inflation, 4-minute deflation. The tourniquet
Kristin M. Mills, Scott Sadler, Karen Peterson and Lorrin Pang
aged 72 years or older was $19,440 (for those who sought medical care for their falls), which translates to approximately $28,430 in 2012, adjusting for general inflation. 3 About 20%–30% of elderly who fall will suffer a serious injury that can limit independence or increase the risk of untimely
Tania Pereira, John Durocher and Jamie Burr
strength and power. Pearson correlation was used to determine if there was a relationship between HR inflation and riding intensity (%VO 2 max), thus indicating whether riding intensity influenced the level of inflation. Pearson correlation was also used with perception of effort and age, experience, and