The purpose of the current study was to investigate the effects of finger strength training (ST) on finger strength, independence, force control, and adaptations in multifinger coordination. Thirty-three healthy, young (23.0 ± 2.9 years) subjects were randomly assigned into 4 groups. Group 1 (G1) trained all fingers together, Group 2 (G2) trained individual fingers without restricting movements of the non-training fingers, and Group 3 (G3) trained individual fingers while restricting the movement of the nontraining fingers. The control group (G0) did not undergo any training. A vertically hanging load was attached to a spring that passed through a pulley. The other end of the string extended to the horizontal plane and had thimbles attached to it. Subjects were asked to rest their forearm on the table and lift the load by inserting their fingers into the thimbles. The training protocol lasted 6 weeks. Identical experimental tests were conducted 4 times, biweekly, across the 6-week training. Force coordination and moment coordination, defined as synergies stabilizing the resultant force and the resultant moment of all finger forces, in a multifinger pressing task were quantified using the Uncontrolled Manifold (UCM) analysis. The UCM analysis allocates motor variability into two components, one in the null space of a motor task and the other perpendicular to the null space. During multifinger pressing tasks, multifinger coordination exists when the variability in the null space is greater than the variability in the subspace perpendicular to the null space. The multifinger coordination was quantified as the difference between the variance within the null space and that perpendicular to the null space, normalized by the total variance. Thus, the coordination measure in our analysis is a unitless variable. A greater coordination measure indicates better multifinger coordination. Moment-stabilizing multifinger coordination increased only in G1 (from 1.197 ± 0.004 to 1.323 ± 0.002, p < .01), and force-stabilizing coordination increased only in G3 (from 0.207 ± 0.106 to 0.727 ± 0.071, p < .01). Finger strength, measured by the maximal voluntary finger force of pressing 4 fingers, increased significantly in all training groups (from 103.7 ± 3.1 N to 144.0 ± 3.6 N for training groups, all p < .001). Finger-force errors, quantified by the deviations between the required force profiles (20% maximal voluntary force) presented to the subjects and the actual force produced, decreased significantly with ST for all the training groups (all p < .05). Finger independence also decreased significantly for all the training groups (p < .05). We conclude that the neuromuscular system adaptations to multifinger ST are specific to the training protocol being employed, yielding improvements in different types of multifinger coordination (i.e., coordination-specific ST), finger-force control, and finger strength and a decrease in finger independence. Finger independence, depending on the nature of the task, might or might not be favorable to certain task performances. We suggest that ST protocol should be carefully designed for the improvement of specific coordination of multieffector motor systems.
Jae Kun Shim, Jeffrey Hsu, Sohit Karol and Ben F. Hurley
Martin Buchheit, Mathieu Lacome, Yannick Cholley and Ben Michael Simpson
Within the tactical periodization training approach, tactical, technical, physiological, and psychological elements are rarely trained in isolation, which is believed to improve specific motor skill acquisition and accelerate tactical learning. 1 In fact, daily training components are structured
Matthew R. Rhea and Derek Bunker
Baseball demands speed, power, and quickness. To perform at a high level, and avoid injuries that are common among baseball players, an evaluation of current trends in strength and conditioning practices is helpful. Based on the demands of the sport and the injury risks, qualified strength and conditioning professionals can develop effective baseball-specific conditioning programs. This commentary briefly covers historical aspects of baseball conditioning, recent injury trends, current practices among elite baseball professionals, and provides suggestions for future improvements in training.
Neil Armstrong and Jo Welsman
in mL·kg −1 ·min −1 has been reported to be unrelated to maturity status ( 11 ), but with body mass controlled for using allometry, it has been demonstrated that there are significant, sex-specific, positive effects of maturity status on peak V ˙ O 2 independent of age ( 9 ). Fat tissue does not
Alyssa J. Wagner, Casey D. Erickson, Dayna K. Tierney, Megan N. Houston and Cailee E. Welch Bacon
Eating disorders in female athletes are a commonly underdiagnosed condition. Better screening tools for eating disorders in athletic females could help increase diagnosis and help athletes get the treatment they need.
Focused Clinical Question:
Should screening tools be used to detect eating disorders in female athletes?
Summary of Key Findings:
The literature was searched for studies that included information regarding the sensitivity and specificity of screening tools for eating disorders in female athletes. The search returned 5 possible articles related to the clinical question; 3 studies met the inclusion criteria (2 cross-sectional studies, 1 cohort study) and were included. All 3 studies reported sensitivity and specificity for the Athletic Milieu Direct Questionnaire version 2, the Brief Eating Disorder in Athletes Questionnaire version 2, and the Physiologic Screening Test to Detect Eating Disorders Among Female Athletes. All 3 studies found that the respective screening tool was able to accurately identify female athletes with eating disorders; however, the screening tools varied in sensitivity and specificity values.
Clinical Bottom Line:
There is strong evidence to support the use of screening tools to detect eating disorders in female athletes. Screening tools with higher sensitivity and specificity have demonstrated a successful outcome of determining athletes with eating disorders or at risk for developing an eating disorder.
Strength of Recommendation:
There is grade A evidence available to demonstrate that screening tools accurately detect female athletes at risk for eating disorders.
Paul A. Borsa, Eric L. Sauers and Scott M. Lephart
Functional training for the purpose of restoring dynamic joint stability has received considerable interest in recent years. Contemporary functional training programs are being designed to complement, rather than replace, traditional rehabilitation protocols. The purpose of this clinical commentary is to present a management strategy for restoring dynamic stability in the posterior cruciate ligament (PCL)-injured knee. The strategy presented integrates five key concepts: (a) planned variation of exercise, (b) outcomes-based assessment, (c) kinetic chain exercise, (d) proprioception and neuromuscular control, and (e) specificity of activity. Pertinent research findings and a clinical rationale are provided for using functional training in the restoration of dynamic stability in the PCL-injured knee.
Scott J. Dankel, Jeremy P. Loenneke and Paul D. Loprinzi
Previous research has demonstrated that having adequate lower extremity and upper body muscle strength (generally defined as averting the lower tertile or quartile) reduces the risk of all-cause mortality 1 – 3 ; however, less overt is the importance of skeletal muscle strength on cancer-specific
Chun-Hao Wang and Kuo-Cheng Tu
better developed in athletes who are trained in sports involving high temporal and spatial constraints because such experts are considered to be well trained in a specific type of task and may have extensive knowledge of it ( Mori & Shimada, 2013 ). Indeed, findings from research using cognitive
Matheus Hausen, Pedro Paulo Soares, Marcus Paulo Araujo, Débora Esteves, Hilbert Julio, Roberto Tauil, Marcus Junca, Flávia Porto, Emerson Franchini, Craig Alan Bridge and Jonas Gurgel
’ cardiorespiratory fitness, the exercise testing modes lack mechanical specificity to the technical actions performed within the sport. 2 , 3 This oversight might negatively influence the validity of V ˙ O 2 max assessment and compromise the effective detection of ventilatory thresholds (VTs). Subsequently, such
Jarred Pilgrim, Peter Kremer and Sam Robertson
the lowest score. In addition, McCaffrey and Orlick ( 1989 ) found that professionals use specific warm-up programs and take shots on the putting green and practice range before rounds, as well as practice components of their game between rounds. However, it is presently not known how these and other