.8)* Day 4 14.7 (2.3) 15.0 (2.6) 45.9 (7.7) 57.6 (5.7) 118.7 (9.2) 111.9 (9.8) 163.9 (13.6) 169.8 (13.6) Day 5 14.1 (2.1) 15.4 (2.6) 46.2 (7.2) 60.3 (5.8)* 121.5 (8.1)* 113.4 (9.5) 167.7 (10.8)* 173.7 (13.2)* Abbreviations: CSA, cross-sectional area; Dom, dominant; NDom, nondominant. *Significant change
Brett S. Pexa, Eric D. Ryan, Elizabeth E. Hibberd, Elizabeth Teel, Terri Jo Rucinski and Joseph B. Myers
Atsuki Fukutani and Toshiyuki Kurihara
Recent studies have reported that resistance training increases the cross-sectional areas (CSAs) of tendons; however, this finding has not been consistently observed across different studies. If tendon CSA increases through resistance training, resistance-trained individuals should have larger tendon CSAs as compared with untrained individuals. Therefore, in the current study, we aimed to investigate whether resistance training increases tendon CSAs by comparing resistance-trained and untrained individuals. Sixteen males, who were either body builders or rugby players, were recruited as the training group, and 11 males, who did not participate in regular resistance training, were recruited into the control group. Tendon CSAs and muscle volumes of the triceps brachii, quadriceps femoris, and triceps surae were calculated from images obtained by using magnetic resonance imaging. The volumes of the 3 muscles were significantly higher in the training group than in the control group (P < .001 for all muscles). However, a significant difference in tendon CSAs was found only for the distal portion of the triceps surae tendon (P = .041). These findings indicate that tendon CSA is not associated with muscle volume, suggesting that resistance training does not increase tendon CSA.
Josep C. Benitez-Martinez, Jose Casaña-Granell, Yasmin Ezzatvar de Llago, Carlos Villaron-Casales, Gemma V. Espi-Lopez and Fernando Jimenez-Diaz
The supraspinatus muscle has an important role in the stabilization of the glenohumeral joint. Identifying abnormalities concerning its size and the subacromial space in the presence of pain may be relevant to provide more specific treatments focused on the etiology of pain.
To determinate whether painful shoulder causes changes in the supraspinatus cross-sectional area (CSA) and the acromio-humeral distance (AHD) between overhead athletes.
University campus and local sports clubs’ Physical Therapist room.
81 male overhead athletes were divided into 2 groups according to the presence of shoulder pain and clinical symptoms.
Main Outcome Measures:
Ultrasonography measurements of the supraspinatus CSA and the AHD in 2 groups of overhead athletes with and without pain.
In the pain group, the CSA was significantly smaller compared with the no pain group. No differences between groups were found in the AHD measurement.
Shoulder pain in overhead athletes was associated with a reduction in their supraspinatus muscle CSA, but not in the AHD. These findings suggest that muscle atrophy exists in the presence of pain. However, in active overhead athletes, the AHD is not clearly reduced in overhead athletes with shoulder pain. Further studies are needed to understand this condition.
Ui-Jae Hwang, Sung-Hoon Jung, Hyun-A Kim, Jun-Hee Kim and Oh-Yun Kwon
at mid-expiration. 45 , 46 Measurements of abdominal muscle size on MRI included the cross-sectional area (CSA) of the RA and LAW (intrareliability; intraclass coefficient [ICC] = .892). The MRI images were archived for later analysis using a measurement software package on a laptop computer
Keitaro Kubo, Takanori Teshima, Norikazu Hirose and Naoya Tsunoda
The purpose of this study was to compare the morphological and mechanical properties of the human patellar tendon among elementary school children (prepubertal), junior high school students (pubertal), and adults. Twenty-one elementary school children, 18 junior high school students, and 22 adults participated in this study. The maximal strain, stiffness, Young’s modulus, hysteresis, and cross-sectional area of the patellar tendon were measured using ultrasonography. No significant difference was observed in the relative length (to thigh length) or cross-sectional area (to body mass2/3) of the patellar tendon among the three groups. Stiffness and Young’s modulus were significantly lower in elementary school children than in the other groups, while no significant differences were observed between junior high school students and adults. No significant differences were observed in maximal strain or hysteresis among the three groups. These results suggest that the material property (Young’s modulus) of the patellar tendons of elementary school children was lower than that of the other groups, whereas that of junior high school students was already similar to that of adults. In addition, no significant differences were observed in the extensibility (maximal strain) or viscosity (hysteresis) of the patellar tendon among the three groups.
Michael P. Godard, David L. Williamson, David A. Porter, Gregory A. Rowden and Scott W. Trappe
This investigation examined alterations in neuromuscular drive for dynamic and static muscle contractions, muscle strength, and cross-sectional area (CSA) with a 12-week progressive resistance-training program (PRT). Nine healthy men (70.0 ± 1.7 years) were evaluated for maximal and submaximal neuromuscular drive (integrated electromyography [IEMG]), whole-muscle strength, isokinetic power, and thigh CSA. The results demonstrated no significant differences pre- to post-PRT in the submaximal IEMG signals (p > .05). IEMG increased (p < .05) for the maximal static contraction (29% ± 12%) and isokinetic velocities concentrically and eccentrically. There was an increase (p < .05) in maximal static strength (27% ± 5%), isokinetic concentric and eccentric strength, muscle power, IRM (47% ± 6%), and CSA (6% ± 1%; p < .05). The results reveal significant neuromuscular-drive alterations in concentric and eccentric dynamic contractions with PRT in older men and indicate that their neuromuscular drive contributes significantly to improving their concentric and eccentric skeletal-muscle strength.
Lilian França Wallerstein, Valmor Tricoli, Renato Barroso, André L.F. Rodacki, Luciano Russo, André Yui Aihara, Artur da Rocha Correa Fernandes, Marco Tulio de Mello and Carlos Ugrinowitsch
The purpose of this study was to compare the neuromuscular adaptations produced by strength-training (ST) and power-training (PT) regimens in older individuals. Participants were balanced by quadriceps cross-sectional area (CSA) and leg-press 1-repetition maximum and randomly assigned to an ST group (n = 14; 63.6 ± 4.0 yr, 79.7 ± 17.2 kg, and 163.9 ± 9.8 cm), a PT group (n = 16; 64.9 ± 3.9 yr, 63.9 ± 11.9 kg, and 157.4 ± 7.7 cm), or a control group (n = 13; 63.0 ± 4.0 yr, 67.2 ± 10.8 kg, and 159.8 ± 6.8 cm). ST and PT were equally effective in increasing (a) maximum dynamic and isometric strength (p < .05), (b) increasing quadriceps muscle CSA (p < .05), and (c) decreasing electrical mechanical delay of the vastus lateralis muscle (p < .05). There were no significant changes in neuromuscular activation after training. The novel finding of the current study is that PT seems to be an attractive alternative to regular ST to maintain and improve muscle mass.
Aliza K. Nedimyer, Brian G. Pietrosimone, Brittney A. Luc-Harkey and Erik A. Wikstrom
such as cross-sectional area (CSA), thickness, and width, that could provide valuable insights into how a RRI alters muscle morphology; but, there exists limited research on this topic. 12 , 14 – 16 Similarly, clinician-oriented measures of navicular drop, muscle strength, and postural control can
Marta C. Erlandson, Shonah B. Runalls, Stefan A. Jackowski, Robert A. Faulkner and Adam D.G. Baxter-Jones
measures such as cross-sectional area (CSA) and section modulus ( Z ), which provide information about the structural dimensions of bone ( 10 , 11 , 23 ). During the growing years, bone responds to increased mechanical load by the apposition of bone to the endosteal as well as the periosteal surface or by
Paige E. Rice, Herman van Werkhoven, Edward K. Merritt and Jeffrey M. McBride
bone mineral density, bone mineral content, and bone-strength indices, which may influence factors reflective of bone health such as stress–strain index and ultimate fracture load. 5 Muscle cross-sectional area, muscle strength, peak force, and peak power measurements during jumping have shown to