analysis (825 of a possible 1035 tests were analyzed throughout the season). Players were required to lie beneath the GroinBar Hip Strength Testing System (Vald Performance, Albion, Australia) in a supine position with their knee joints at an angle of 60°. Bar height was customized for each player to
Samuel Ryan, Thomas Kempton, Emidio Pacecca and Aaron J. Coutts
Frederico Ribeiro Neto, Rodrigo Rodrigues Gomes Costa, Ricardo Tanhoffer, Martim Bottaro and Rodrigo Luiz Carregaro
/wk), (3) active (3–6 h/wk), and (4) very active/athlete (>6 h/wk). This study was approved by the ethics committee of the Sarah Network of Rehabilitation Hospitals (protocol no 53341616.0.0000.0022), and all volunteers signed an informed consent form. Procedures Maximum strength testing of elbow flexion
Melissa DiFabio, Lindsay V. Slater, Grant Norte, John Goetschius, Joseph M. Hart and Jay Hertel
participants) before being repeated on the involved (ACLR participants) or nondominant limb (healthy participants). The dominant limb was defined as the preferred kicking leg. Strength Assessment Isokinetic and isometric strength testing was completed for knee extension and flexion using the Biodex System 3
Thomas Hall, Marc P. Morissette, Dean Cordingley and Jeff Leiter
Reliable assessment of neck strength is required to fully understand the role of decreased neck strength as a risk factor for concussion. The purpose of this study was to assess the intrarater and interrater reliability of a standardized isometric neck-strength-testing protocol using a custom-designed frame, and a digital force gauge. Assessment of intrarater and interrater reliability of a custom neck-strength-testing frame and protocol yielded intraclass correlation values > .890 and > .900 when using maximum peak and average peak values of neck strength, respectively. Our neck-strength-testing frame and protocol provided data of good to excellent reliability, and may be used in future studies to investigate the relationship between neck strength and incidence of injuries.
Gulcan Harput, Volga B. Tunay and Matthew P. Ithurburn
dynamometer force arm was secured on the shank, 2 cm above the lateral malleolus. 19 Before muscle strength testing, participants were allowed 3 submaximal voluntary isometric quadriceps and hamstring contractions to familiarize themselves with the testing procedures and to warm up. 19 During the formal
James R. Rosemeyer, Bradley T. Hayes, Craig L. Switzler and Charlie A. Hicks-Little
Core stability has been shown to affect lower-extremity motion, but activation of the core has also been observed just before movements of the upper extremity. However, there is limited evidence regarding the effects that core musculature has on upper-extremity strength.
To determine the effects of core fatigue on maximal shoulder strength.
Sports-medicine research laboratory.
23 participants (15 male and 8 female, age 21.3 ± 2.5 y, height 174.5 ± 10.3 cm, weight 71.3 ± 12.0 kg).
All participants performed maximal voluntary isometric contractions in 3 different planes (sagittal, frontal, transverse) of shoulder-joint motion. A core-fatiguing protocol was conducted, and the same 3 shoulder-strength tests were repeated and compared with the initial measurements.
Main Outcome Measures:
Strength measures were recorded in kilograms with a dynamometer.
Results showed a significant decrease in strength in the frontal (−0.56 ± 1.06 kg, P = .020) and transverse (−0.89 ± 1.49 kg, P = .012) planes but not in the sagittal plane (−0.20 ± 0.98 kg, P > .05). Furthermore, regardless of the specific strength test measured, results revealed that the 1st (−7.05% ± 11.65%, P = .012) and 2nd (−5.71% ± 12.03%, P = .042) strength-test measurements after the fatiguing protocol were significantly decreased, while the 3rd strength-test measurement (−4.19% ± 12.48%, P = .140) did not show statistical significance.
These results indicate that decrease in core stability may have an influence on shoulder strength. The literature suggests that the core is designed for endurance, and this study helps validate its recovery properties. Further research is needed to determine the significance of this effect and how injury rates coincide.
Jeanne F. Nichols, Lori M. Hitzelberger, Jennifer G. Sherman and Patricia Patterson
This study examined the efficacy of a progressive resistance exercise program, using equal concentric/eccentric (CE) or greater eccentric/concentric (GE) workloads, for increasing strength and improving functional abilities of community-dwelling older adults. Sixty men and women were randomly assigned to one of three groups: CE, GE, or control. All strength testing and training took place on six Lifecircuit machines. Functional tests included a bas carry, weighted stair climb, shelf task 1-RM, and static balance. Significant interactions in strength tests were noted for the chest, back, and shoulder exercises. GE improved in shoulder strength more than CE and control For functional measures, all weight trainers were grouped and compared to controls. A significant interaction occurred for the stair climb and balance with the exercise groups decreasing stair climb time by 11% and increasing balance time by 26%. Relative improvements by weight trainers of 12% for the shelf task and 7% for the bag carry were not significant. These data indicate that a moderate intensity resistance program can have positive effects on tasks required for everyday function.
Taina Rantanen and Eino Heikkinen
The aim of this study was to examine alterations in maximal isometric strength of multiple muscle groups over 5 years and to compare strength changes between individuals who maintained a high level of physical activity and others who did not. As a part of the Evergreen Project, 20 men and 59 women participated in at least one strength test at the age of 80 and again 5 years later. Men displayed no decrease in lean body mass over the follow-up. and the only significant strength decrease was in elbow flexion strength. In women, both lean body mass and muscle strength decreased significantly (except trunk extension strength). Overall, those men and women who were considered to have maintained a high level of activity retained their strength at a higher level than the more sedentary participants. Older people should be encouraged to continue physically demanding activities to maintain muscle strength at an adequate level for independent living.
Eleftherios Kellis, Spiros Kellis, Vasilios Gerodimos and Vasiliki Manou
The reliable examination of isokinetic parameters in young athletes is important for the establishment of appropriate strength testing protocols. The purpose of this study was to examine the reliability of peak moments, non-preferred/preferred leg and reciprocal ratios during isokinetic knee efforts in young soccer players. Thirteen circumpubertal (age = 13.0 ± 0.4 years) soccer players performed maximum knee extension and flexion efforts at 30, 120 and 180°·s1 in two occasions, a week apart. The reliability of the peak moments was high, with reliability coefficients ranging from 0.71 to 0.98. The non-preferred/preferred leg and reciprocal ratios demonstrated moderate to high reliability (coefficients ranged from 0.42 to 0.87). The reliable examination of moments of force and ratio measurements during eccentric tests and at fast angular velocities in young soccer players requires extensive familiarization of the subjects prior to the main test.
Claire Peel, Carolyn Utsey and Jan MacGregor
This study aimed to evaluate the effects of an 8-week supervised exercise program on physiological measurements during treadmill walking, muscle strength, functional performance, and health status in older adults limited in physical function. Twenty-four participants were randomly assigned to an exercise group (EG, N = 13) or a control group (CG, N = 11), and were evaluated before and after the exercise program (EG) or 8-week period (CG). Evaluations included a progressive treadmill lest, strength testing, the Physical Performance Test (PPT), and the SF-36 Health Survey. The exercise program consisted of 3 sessions per week of brisk walking and strengthening exercises. The EG demonstrated increases in cardiorespiratory fitness and increases in treadmill walking time. The EG also demonstrated increases in force production in 3 of the 6 muscle groups that were tested. Both the EG and CG demonstrated improvements in PPT scores and in 2 health concepts on the SF-36 Health Survey.