Construction of a Muscular Strength Test for Boys in Grades 4, 5, and 6

Abstract

In this study, a strength test for boys 9 through 12 years of age in grades 4, 5, and 6 was constructed based upon cable tension strength tests. From 18 cable tension strength tests, the following four were selected by multiple correlation procedures: shoulder extension, trunk extension, knee extension, and ankle plantar flexion (ankle extension). The total of these four tests was designated the strength composite. Norms were prepared based on age and weight, utilizing Roger's method in the construction of Strength Index norms; the subjects were 826 boys from ten communities located in various parts of Oregon. A strength quotient was derived by dividing the achieved by the norm strength composite and multiplying by 100.     

Isometric Knee Extension and Plantar Flexion Muscle Fatigue and Fiber Type Composition in Female Distance Runners

Abstract

Plantar flexion and knee extension fatigue patterns elicited by 25 serial isometric contractions were assessed on eight female distance runners. Fiber type composition of the vastus lateralis and gastrocnemius muscles was examined by a needle biopsy technique. Two different isometric exercise regimens were administered: 10-sec contractions separated by 5-sec intertrial rest (10:5) designed to elicit a rapid rate of fatigue, and 10-sec contractions separated by 20-sec intertrial rest (10:20) designed to induce less fatigue. No fatigue pattern was found for the 10:20 regimen which was consistent with previous data on male distance runners but unlike male power athletes who did exhibit significant fatigue. Significant fatigue decrements were found for the 10:5 knee extension (55.7%) and plantar flexion (75.8%) conditions. Fiber type composition and fatigue decrements did not correlate. Knee extension and plantar flexion maximum strength correlated significantly with the amount of fatigue induced with r's of .82 and .83, respectively. For each separate muscle group, maximum isometric strength was a better predictor of fatigability than fiber type composition. Even though differences in maximal strength and muscle mass existed between knee extension and plantar flexion muscle groups, elicited fatigue curves were similar in pattern differing only in absolute level. High versus low strength classification analysis showed similar knee extension but dissimilar plantar flexion fatigue patterns. Results suggest that the role of fiber type composition, muscle mass, and maximum strength level as they influence local muscular fatigue patterns must be elucidated for each muscle group separately.     

The effects of plyometric exercise on unilateral balance performance

Abstract

The purpose of this study was to determine the effects of plyometric exercise on unilateral balance performance. Nine healthy adults performed baseline measurements on the dominant limb that consisted of: a 20-s unilateral stability test on a tilt balance board, where a higher stability index represented deterioration in balance performance; isokinetic plantar flexion torque at 0.52 and 3.14 rad · s^?1; muscle soreness in the calf region; and resting plantar flexion angle. Plyometric exercise consisted of 200 counter-movement jumps designed to elicit symptoms of muscle damage, after which baseline measurements were repeated at 30 min, 24, 48, and 72 h. Perceived muscle soreness of the calf region increased significantly following the plyometric exercise protocol (F_4,32 = 17.24, P < 0.01). Peak torque was significantly reduced after the plyometric exercise protocol (F_4,32 = 7.49, P < 0.05), with greater loss of force at the lower angular velocity (F_4,32 = 3.46, P < 0.05), while resting plantar flexion angle was not significantly altered compared with baseline values (P > 0.05). The stability index was significantly increased (F_4,32 = 3.10, P < 0.05) above baseline (mean 2.3, s = 0.3) at 24 h (3.3, s = 0.4), after which values recovered. These results indicate that there is a latent impairment of balance performance following a bout of plyometric exercise, which has implications for both the use of skill-based activities and for increased injury risk following high-intensity plyometric training.     

Selected Measures of Angular Displacement,Strength, and Flexibility in Subjects With and Without Shin Splints

Abstract

The purpose of this study was to determine if angular displacement between the calcaneus and the midline of the lower leg while running is related to shin splints. A secondary purpose was to compare the strength and flexibility of ankle-joint plantar flexion, dorsal flexion, inversion, and eversion of shin-splint-injured and non-shin-splint-injured subjects. Two groups of conditioned female athletes were randomly selected to participate in this study. One group had a previous history of chronic shin splints, and the other group had no history of shin-splint injury. Angular displacement between the calcaneus and the midline of the lower leg was measured from motion picture film (100 frames/second) taken while the subjects were running at two speeds, 3m/second and 5m/second. A cable tensiometer was used to measure plantar flexion, dorsal flexion, and inversion and eversion strength at the ankle joint; and a goniometer was used to measure the flexibility of the plantar flexors, dorsiflexors, invertors, and evertors at the ankle joint. The results indicated that a shin-splint-injured leg had greater angular displacement between the calcaneus and the midline of the lower leg than a healthy leg, and that shoes and speed of running had an influence upon the amount of angular displacement. In addition, the muscular strength of the plantar flexor muscle was greater in the shin-splint subjects than in the non-shin-splint subjects.     

Contributive Components in the Vertical Jump

Abstract

The degree of contribution to performance of the vertical jump by leg components plantar flexors, knee extensors, and hip extensors was determined experimentally and tested by analysis of covariance. One control and four experimental groups from 100 college men at Brigham Young University were randomly assigned to varying muscle strengthening programs for 8 weeks. Initial and final vertical jump tests and strength measures were administered. Gains in the vertical jump significant beyond the .05 level were registered by experimental groups which strengthened knee and/or hip extensors. Control and plantar flexor strengthening groups did not register significant jump gains. Each experimental group registered significant isotonic strength gains in the programed muscle groups.     

The effects of plyometric exercise on unilateral balance performance

The purpose of this study was to determine the effects of plyometric exercise on unilateral balance performance. Nine healthy adults performed baseline measurements on the dominant limb that consisted of: a 20-s unilateral stability test on a tilt balance board, where a higher stability index represented deterioration in balance performance; isokinetic plantar flexion torque at 0.52 and 3.14 rad s(-1); muscle soreness in the calf region; and resting plantar flexion angle. Plyometric exercise consisted of 200 counter-movement jumps designed to elicit symptoms of muscle damage, after which baseline measurements were repeated at 30 min, 24, 48, and 72 h. Perceived muscle soreness of the calf region increased significantly following the plyometric exercise protocol (F(4,32) = 17.24, P < 0.01). Peak torque was significantly reduced after the plyometric exercise protocol (F(4,32) = 7.49, P < 0.05), with greater loss of force at the lower angular velocity (F(4,32) = 3.46, P < 0.05), while resting plantar flexion angle was not significantly altered compared with baseline values (P > 0.05). The stability index was significantly increased (F(4,32) = 3.10, P < 0.05) above baseline (mean 2.3, s = 0.3) at 24 h (3.3, s = 0.4), after which values recovered. These results indicate that there is a latent impairment of balance performance following a bout of plyometric exercise, which has implications for both the use of skill-based activities and for increased injury risk following high-intensity plyometric training.     

The Effect of Venue and Wind on the Distance of a Hammer Throw

Abstract

The Reynolds' Balance Test was administered to selected groups of varsity athletes, physical education majors, and liberal arts majors. Significant differences in mean balance scores were found between all groups. The performance of the groups was, in descending order: varsity athletes, physical education majors, and liberal arts majors. It was suggested that the Reynolds' Balance Test gives promise of being a valuable addition to physical education testing programs.     

Effect of a Single Day's Swimming on Selected Components of Athletic Performance

Abstract

The purpose of this investigation was to study the effect of swimming on selected components of athletic performance as measured by the following tests: back strength, leg strength, bicycle ergometer (combination of strength and endurance, but predominantly endurance), and vertical jump (explosive power). Subjects were pretested for three days on each test, after which they participated in 45 minutes of swimming, and performance was tested oh one test one hour after the swim on any given day. A single day's swimming was found to significantly affect the vertical jump, but other performance tests were not affected.     

Trampoline Versus Resistance Training in Young Adults: Effects on Knee Muscles Strength and Balance

ABSTRACT

Purpose: Trampoline parks are becoming popular in many countries, providing recreational facilities for children and adults. This study investigated the effects of trampoline training on knee muscles strength and balance in young adults. Methods: Twenty-six participants (14 males, 12 females) were randomized into trampoline training (TT) and resistance training (RT) groups to undergo a 6-week supervised intervention program (2 × 30 min per week). TT group performed basic trampoline exercises while the RT group performed resistance training targeting lower extremities muscles. Peak knee extension and flexion torque, postural sway characteristics, and Y balance test (YBT) performance were evaluated before and after the intervention. A mixed model analysis of variance (group × time) was applied. Results: After training there were significant improvements in knee extension torque (mean difference_post-pre [95% CI], TT: 0.27 [0.00, 0.54] N?m/kg, RT: 0.31 [0.09,0.54] N?m/kg, p = .001), knee flexion torque (TT: 0.25 [0.17,0.33] N?m/kg, RT: 0.21 [0.08,0.34] N?m/kg, p < .001), and dynamic balance (YBT composite scores, mean difference_post-pre [95% CI], TT: 4.9 [?0.3, 10.2]%, RT: 5.2 [2.4,8.0]%, p = .001). No difference between groups was found. Conclusion: Trampoline training can be as effective as resistance training for improving knee muscles strength and dynamic balance in young men and women.     

Relationship of Individual Differences and Subsequent Changes in Static Strength with Speed of Forearm Flexion Movement

Abstract

This study investigated the relationship between strength and speed of forearm flexion and compared the effect of three methods of training on speed of forearm flexion movement. Ninety-one university freshmen were tested for maximum static strength, forearm mass, and speed of forearm flexion. They were assigned to four groups: control, speed of movement, isometric, and isotonic. After an 8-week experimental program, subjects were tested again for strength, mass, and speed of forearm flexion movement. Low positive relationships, significant at the .05 level, between static strength and speed of forearm flexion were found in this study. When static strength was related to the mass which was moved during movement, correlations between strength/mass and speed were not significant. The results of both correlational computations and covariance analysis indicated that increasing the strength of the muscles which move a limb does not result in a corresponding increase in the speed with which the limb can be moved.     

Effect of bike-fit in the perception of comfort,fatigue and pain

ABSTRACT

The aim of this study was to assess the influence of different bike positions on the perception of fatigue, pain and comfort. Twenty cyclists underwent three tests that involved cycling for 45 min at their individual 50% peak aerobic power output while adopting different positions on the bike. Participants performed the cycling tests adopting three positions defined by two parameters (knee flexion angle [20°, 30°, 40°] and trunk flexion angle [35°, 45°, 55°]) in random order. Angles were measured using a 2D motion analysis system during cycling and applying Fonda’s correction factor. Perceptions of comfort, fatigue and pain were reported before the end of each test. The combination of 40° knee flexion and 35° trunk flexion was perceived as the most uncomfortable position. Moreover, greater knee flexion had a negative effect on trunk comfort, accompanied by greater levels of fatigue and pain perception in the anterior part of the thigh and knee. In conclusion, cyclists perceived the most comfortable position to be when the saddle height was within the recommended knee angle (30° calculated from the offset position or 40 ± 4.0° of absolute value). Upright trunk was found to be the most comfortable position for recreational cyclists, where aerodynamics is not so important. Cyclists’ bike perceptions should be taken into account when it comes to choosing the most beneficial position, since this can play a role in injury prevention and enhance cycling performance.     

Effects of latissimus dorsi length on shoulder flexion in canoeists,swimmers, rugby players,and controls

BackgroundShoulder flexion requires an optimal length of the latissimus dorsi muscle in order to allow full lateral rotation of the humerus and upward scapular rotation. If shoulder flexion (in an externally rotated position) is restricted, this may predispose the individual to shoulder pathology. Sports such as swimming and canoeing have increased shoulder injuries and require high levels of latissimus dorsi muscle activity, which may create muscle hypertrophy and increased stiffness, resulting in a loss of muscle length. The objective of this study was to investigate if differences are present in shoulder flexion in internally and externally rotated positions across different sports (swimming, canoeing, and rugby) and a non-sporting control group.MethodsOne hundred subjects (40 physically active controls, 25 professional Rugby Union players, 20 elite, national-level canoeists (slalom), and 15 elite, national-level swimmers) participated in this study. Shoulder flexion range of motion was measured using a standard goniometer, with the arm elevated in either full external or internal rotation.ResultsA significant difference in shoulder flexion range was observed between canoeists and swimmers, canoeists and controls, rugby players and canoeists, rugby players and swimmers, and controls and swimmers in the external rotation position (p < 0.017), but not between controls and rugby players (p = 0.12). For the internal rotation position, swimmers significantly differed from canoeists, rugby players, and controls (p < 0.017), but there were no significant differences between rugby players, canoeists, and controls (p > 0.07).ConclusionThis study found that the length of the latissimus dorsi differs between sports and controls in accordance with the specific physical demands of their sport.     

A Commentary On Children and Fitness: A Public Health Perspective

Abstract

Head rotation, shoulder extension and rotation, ankle plantar and dorsiflexion, hip flexion, and sit and reach (SR) scores were examined in 41 women and 39 men, aged 45–75 years. The SR gave more reproducible data than the other measurements (intraclass test/retest correlation over 8 months, r = .83). SR scores were independent of standing height (r ² = .068) but were greater in women (p < .002). The flexibility at all joints was less than reported for young adults. There were age-related decreases of flexibility scores for the head and shoulder joints (p < .01), with a parallel trend (p < .05) for ankle plantar flexion and SR scores (the last only after inclusion of an age-gender interaction term). A principal components analysis identified three factors (tentatively identified as general trunk, ankle, and shoulder flexibility) accounting for 55.9% of total variance. SR scores had a moderate correlation with the first factor (r = .61) but only weak correlations with the second and third. Although the SR test is the most reliable simple instrument, it provides only limited information about the flexibility at other joints in an older population.     

Relationship of proprioception,cutaneous sensitivity,and muscle strength with the balance control among older adults

BackgroundBalance impairment is one of the strongest risk factors for falls. Proprioception, cutaneous sensitivity, and muscle strength are 3 important contributors to balance control in older adults. The relationship that dynamic and static balance control has to proprioception, cutaneous sensitivity, and muscle strength is still unclear. This study was performed to investigate the relationship these contributors have to dynamic and static balance control.MethodsA total of 164 older adults (female = 89, left dominant = 15, age: 73.5 ± 7.8 years, height: 161.6 ± 7.1 cm, weight: 63.7 ± 8.9 kg, mean ± SD) participated in this study. It tested the proprioception of their knee flexion/extension and ankle dorsi/plantarflexion, along with cutaneous sensitivity at the great toe, first and fifth metatarsals, arch, and heel, and the muscle strength of their ankle dorsi/plantarflexion and hip abduction. The Berg Balance Scale (BBS) and the root mean square (RMS) of the center of pressure (CoP) were collected as indications of dynamic and static balance control. A partial correlation was used to determine the relationship between the measured outcomes variables (BBS and CoP-RMS) and the proprioception, cutaneous sensitivity, and muscle strength variables.ResultsProprioception of ankle plantarflexion (r = –0.306, p = 0.002) and dorsiflexion (r = –0.217, p = 0.030), and muscle strength of ankle plantarflexion (r = 0.275, p = 0.004), dorsiflexion (r = 0.369, p < 0.001), and hip abduction (r = 0.342, p < 0.001) were weakly to moderately correlated with BBS. Proprioception of ankle dorsiflexion (r = 0.218, p = 0.020) and cutaneous sensitivity at the great toe (r = 0.231, p = 0.041) and arch (r = 0.285, p = 0.002) were weakly correlated with CoP-RMS in the anteroposterior direction. Proprioception of ankle dorsiflexion (r = 0.220, p = 0.035), knee flexion (r = 0.308, p = 0.001) and extension (r = 0.193, p = 0.040), and cutaneous sensitivity at the arch (r = 0.206, p = 0.028) were weakly to moderately correlated with CoP-RMS in the mediolateral direction.ConclusionThere is a weak-to-moderate relationship between proprioception and dynamic and static balance control, a weak relationship between cutaneous sensitivity and static balance control, and a weak-to-moderate relationship between muscle strength and dynamic balance control.     

超重肥胖老年女性下肢肌力及平衡能力的运动干预实验研究

目的：针对超重肥胖老年人进行循环训练运动干预设计,探讨循环训练对超重肥胖老年人下肢肌力及平衡能力的影响。方法：以34名老年女性为受试者,分为超重组和对照组,均坚持12周循环训练干预,比较干预前后两组受试者双侧下肢膝踝屈伸等速肌力、静动态平衡能力、计时"起立-行走"时间和Berg平衡量表得分情况。结果：运动干预12周后,两组下肢膝踝屈伸肌标准化峰值力矩、屈伸肌肌力比值和双侧肌力比值、静态与动态平衡能力、Berg平衡量表得分及计时"起立-行走"时间均有显著提高;且超重组的右膝伸肌标准化峰值力矩的提高程度明显高于对照组。结论：循环训练可以显著提高老年人的下肢肌力和平衡能力,且对提高超重肥胖老年人下肢伸肌肌力有更明显的改善效果,是预防老年人跌倒的有效运动方法。     

Endurance tests are the most reliable core stability related measurements

PurposeTo determine the intra-tester reliability of clinical measurements that assess five components related to core stability: strength, endurance, flexibility, motor control, and function.MethodsParticipants were 15 college-aged males who had not suffered any orthopedic injury in the past year. Core strength measurements included eight isometric tests and a sit-up test. The four core endurance tests were the trunk flexor test, trunk extensor test, and bilateral side bridge tests. Flexibility tests included the sit-and-reach test and active range of the trunk and hip joint motions. Proprioception via passive reposition tests of the hips and a single limb balance test on an unsteady platform were used to evaluate core motor control. Functional measurements consisted of a squat test and a single leg hop test for time and distance. Measurements were performed during two data collection sessions with a week's rest between the sessions. Intra-class correlation coefficients were calculated to establish reliability.ResultsThe overall intra-rater reliability for all core stability related measurements ranged from low (ICC = 0.35, left hip reposition) to very high (ICC = 0.98, sit-and-reach). As a group, the core endurance tests were observed to be the most reliable.ConclusionThere are highly reliable tests in each of the five groups. Overall, core endurance tests are the most reliable measurements, followed by the flexibility, strength, neuromuscular control, and functional tests, respectively.     

Effect of Kinesio Taping and balance exercises on postural control in amateur soccer players: A randomised control trial

ABSTRACT

The objective of this study was to determine the effect of Kinesio Taping (KT), alone or together with balance exercises (BE), on parameters related to postural control, such as dynamic balance, static balance and flexibility. Forty-four male amateur soccer players (mean age 24.45 (4.79) years) were randomly allocated to 3 groups: KT+BE that received KT and BE (n = 16); KT_p+BE, in which the KT was used as a placebo (n = 15) and KT alone (n = 13). The intervention period lasted 4 weeks. Star Excursion Balance Test (SEBT), Unipedal Stance Test (UST) and the Toe Touch Test (TTT) were assessed at baseline (pre), two weeks after beginning the treatment (mid) and after the intervention (post). We observed a significant improvement on the SEBT (mid and post-treatment) and the UST (post-treatment), but not on the TTT in either KT+BE or KT_p+BE groups post treatment. No differences were found either in KT group at any time point or between groups in any variable studied. In conclusion, KT functional correction technique does not improve static and dynamic balance when applied alone, whereas BE alone or combined with KT significantly improves these variables. None of these techniques has any effect on flexibility.

Abbreviation: KT: Kinesiotaping; BE: Balance exercises; KTp: Placebo Kinesiotaping; UST: Unipedal Stance Test; SEBT: Star Excursion Balance Test; TTT: Toe Touch Test     

Static Strength Increase and Its Effect upon Triceps Surae Reflex Time

Abstract

This study was to investigate the effect of increased muscle strength on the duration of the triceps surae reflex time. Subjects were 60 students within the age range of 18 to 20 years. The subjects were divided into two groups of equal size—a control and an experimental group. The experimental group performed isometric and isotonic plantar flexor muscle resistance exercises for 40 min. twice a week for a period of 6 weeks. The subjects were tested for plantar flexor static strength and triceps surae reflex time at approximately the same time of day prior to, and at the termination of, the training period. For the experimental group, the statistical analysis revealed a significant decrease in the triceps surae reflex time following strength training. The results of this study appear to warrant the conclusion that an increase in static strength through training has a significant shortening effect upon the triceps surae reflex time.     

The Reliability and Validity of Selected Physical Fitness Tests for High School Girls

Abstract

The Rogers' Strength Test, the Kraus-Weber Test of Minimum Muscular Fitness, and a battery of motor fitness tests were administered to 169 freshmen, sophomore, and junior girls at Shoreline High School, Seattle, Washington. Each test was administered two or more times in order to investigate the reliability of the tests. The results seemed to indicate that the Rogers' Strength Test and Washington Battery were reliable, that those who scored high on the Washington Battery and on the PFI had a much lower percentage of failures on the Kraus-Weber test than did those with poor Washington Battery and PFI scores, and that there was a moderate correlation (.54) between the Washington Battery and the PFI.     

Physical Characteristic,Perceptual-Motor,and Intelligence Differences between Third- and Sixth-Grade Children

Abstract

The following measures were recorded for third- and sixth-grade children: height; weight; grip strength of the dominant and nondominant hands; elbow flexion and elbow extension strength; hip flexion and hip extension strength; dynamic balance; ball-throwing accuracy; speed of hand-arm movement; eye-hand coordination; stimulus discrimination and hand speed; perceptual ability; academic achievement; and intelligence. It was concluded that sixth-grade boys had, in general, the most favorable recorded measures, followed by sixth-grade girls, third-grade boys, and third-grade girls, these differences usually being significant.