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Background: The purpose of this study was to investigate the effects of a home-based muscle power training program on muscle strength and power, functional performance, and physical activity behavior in individuals at least 6 months posttotal knee arthroplasty. Methods: Twelve men and women, mean age 63.9 (6.8) and 6 months to 2 years posttotal knee arthroplasty unilateral or bilateral), completed this study. Participants were randomly assigned to the home-based power training intervention or step-monitoring comparison group. Quadriceps muscle strength and power, 6-minute walk test, functional leg power, and habitual walking behavior (average daily steps, minutes per week of moderate to vigorous physical activity) were assessed before and after intervention and then compared between and within groups. Results: The authors found no significant differences between the groups on amount of change in any of the outcomes, but mixed results on differences within each of the groups on the outcome measures. Conclusion: There were no differences between the groups for amount of change on the outcome measures the authors selected. Although within group differences varied slightly for each group, it was not enough to justify the more expensive home-based power training over the simpler step-monitoring intervention. [ABSTRACT FROM AUTHOR]

Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 [+ or -] 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a single-legged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury--predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/ valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes. KEY WORDS ACL, hop, landing; neuromuscular, drop jump

Byline: Alexis Ortiz, PT, PhD, SCS, CSCS (Physical Therapy Program, School of Health Professions, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico, alexisortiz@cprs.rcm .upr.edu, Department of Physical Education [...]

Background and Purpose: Test-retest reliability has not been previously reported for the instrumented modified Clinical Test of Sensory Interaction on Balance (i-mCTSIB) utilizing the Neurocom Very Simple Rehab (VSR) Sport force plate. The VSR Sport is a portable, relatively inexpensive force plate system utilized to assess postural stability in various populations. Therefore, the purpose of this study is to determine the test-retest reliability, standard error of measurement (SEM), and minimal detectable change (MDC) of the i-mCTSIB when assessed using the VSR Sport in a sample of healthy, older adults. Methods: This was a methodological study with 20 healthy, older adults between the ages of 65 and 85 years. Participants were tested twice in a single session on the i-mCTSIB utilizing the VSR Sport force plate. The mean sway velocity (°/s) measurements for the 2 trials were compared for each test condition to compute intraclass correlation coefficients (ICCs) for each measurement. Standard error of measurements and minimal detectable change at the 90% confidence level (MDC90) were also calculated. Results and Discussion: The test-retest reliability for each of the test conditions ranged from 0.762 to 0.909, which can be broadly interpreted as good-to-excellent reliability. The ICC(2,k) value of 0.898 for the composite score can also be interpreted as excellent reliability. Our results revealed small SEM for all test conditions (SEM = 0.060-0.101) except for the foam surface, eyes closed condition, with an SEM of 0.481. The MDC90 results for all testing conditions ranged from 0.140 to 0.285 except for the foam surface, eyes closed condition, which had an MDC90 = 1.12. Conclusions: The i-mCTSIB measurements utilizing the VSR Sport demonstrated good-to-excellent test-retest reliability. The clinical relevance of this study is that it demonstrates that the VSR Sport is a feasible alternative to other more expensive computerized systems used for the assessment of postural sway. MDC90 scores allow interpretation of change in i-mCTSIB scores following intervention. Practice effects may have contributed to the larger MDC90 for sway scores in the foam surface, eyes closed condition. [ABSTRACT FROM AUTHOR]

Background: Aerobic and muscle-strengthening activities are related to morbidities and mortality. Resistance exercise/strength training items are included in national surveys, but the manner in which muscle-strengthening activity is queried varies among these surveys. Purpose: The purpose of this study was to use different selfreport measures to examine the prevalence of meeting the 2008 Physical Activity Guidelines for Americans regarding muscle-strengthening activities among women. Methods: We surveyed 606 community-dwelling women at 4 points in time across a 1.5- to 3-year time period to determine whether the respondents met the national physical activity guidelines for performing muscle-strengthening activities ≥ 2 days per week. Results: Results were consistent across time but depended on the manner in which the question was asked. If asked to reflect over the past month or a general question about the typical number of days engaged, approximately 40% of women reported engaging in ≥ 2 days per week of resistance exercise/strength training. However, when reports were obtained weekly for 13 weeks, only approximately 18% of respondents met the guidelines. Conclusion: Results indicate that the timing and nature of questioning can substantially influence the selfreported prevalence of muscle-strengthening physical activities for community-dwelling women. [ABSTRACT FROM AUTHOR]

Background: To prepare patients with traumatic brain injury (TBI) for discharge from inpatient rehabilitation, physical therapists may incorporate dual-task gait activities. Reliability of common dual-task measures for people with TBI in inpatient rehabilitation is undetermined. Our purpose was to assess inter-rater and intra-rater reliability and clinical feasibility of dual-task measures [Walking While Talking Test (WWTT), Modified Walking and Remembering Task (mWART), Timed Up and Go-cognitive (TUG-COG)] in inpatient rehabilitation for patients with TBI. Methods: A total of 22 individuals with TBI completing the dual-task measures (WWTT, Walking and Remembering Task (WART), and TUG-COG) in inpatient rehabilitation were rated concurrently by two physical therapists in a single testing session. Sessions were video recorded and rated by the same raters viewing the video 7–10 days later. Raters completed a survey assessing feasibility of conducting the dual-task measures in patients with TBI in inpatient rehabilitation. Data were analyzed by calculating ICC(2,1) for inter-rater reliability and ICC(3,1) for intra-rater reliability. Results: All dual-task measures (WWTT, mWART, TUG-COG) had excellent inter-rater and intra-rater reliability. Raters considered dual-task measures feasible for patients with TBI during inpatient rehabilitation. Conclusions: The WWTT, mWART, and TUG-COG have excellent reliability and appear clinically feasible for incorporation into clinical practice in inpatient rehabilitation following TBI. [ABSTRACT FROM AUTHOR]

Context: The Star Excursion Balance Test (SEBT) is often used to train and assess dynamic balance and neuromuscular control. Few studies have examined hip- and thigh-muscle activation during the SEBT. Objective: To quantify hip- and thigh-muscle activity during the SEBT. Design: Repeated measures. Setting: Laboratory. Participants: 22 healthy individuals, 11 men and 11 women. Methods: EMG measurements were taken as participants completed 3 trials of the anterior (A), medial (M), and posteromedial (PM) reach directions of the SEBT. Main Outcome Measures: Mean EMG data (% maximal voluntary isometric contraction) from the gluteus medius (Gmed), gluteus maximus (Gmax), and vastus medialis (VM) were measured during the eccentric phase of each SEBT reach direction. Test-retest reliability of EMG data across the 3 trials in each direction was calculated. EMG data from each muscle were compared across the 3 reach directions. Results: Test-retest reliability ranged from ICC3,1 values of .91 to .99. A 2-way repeated-measure ANOVA revealed a significant interaction between muscle activation and reach direction. One-way ANOVAs showed no difference in GMed activity between the A and M directions. GMed activity in the A and M directions was greater than in the PM direction. There was no difference in GMax and VM activity across the 3 directions. Conclusion: GMed was recruited most effectively when reaching was performed in the A and M directions. The A, M, and PM directions elicited similar patterns of muscle recruitment for the GMax and VM. During all 3 SEBT directions, VM activation exceeded the 40-60% threshold suggested for strengthening effects. GMed activity also exceeded the threshold in the M direction. GMax activation, however, was below the 40% threshold for all 3 reach directions, suggesting that performing dynamic lower extremity reaching in the A, M, and PM directions may not elicit strengthening effects for the GMax. [ABSTRACT FROM AUTHOR]

Background: Self-report measures have been validated and are widely used. Interest currently lies in the development of simple, valid methods that can be used in any location to determine level of PA in large populations/samples. The purpose of this report is to illustrate tracking of physical activity behaviors and musculoskeletal injury reports on a weekly basis via the Internet. Methods: The Women's Injury Study (WIN) methodology includes use of BRFSS-related physical activity items that are completed online by more than 900 women weekly for an average of 3 years. Results: With more than 45,000 weekly physical activity and injury logs, the percentage of total logs submitted via online records is 91%. Self-reported pedometer steps are consistent with similar, smaller research samples. Conclusions: This report suggests that Internet tracking is a viable means of assessing nearly real-time physical activity, describes the process of developing and monitoring self-reported physical activity behaviors via the Internet, and provides recommendations for others considering such methods. [ABSTRACT FROM AUTHOR]

Background: Effect of muscle strength and balance on falls has not been well researched in healthy older women. The purpose of this study was to compare lower extremity strength and balance in older healthy women during each decade of life and to investigate which factors are different in women with a history of falling. Methods: We retrospectively studied 240 women age 50-89 y. Measures of muscle strength, postural stability, and incidence of falls over the past year were obtained from client charts at Texas Woman's University's Health Promotion & Research Center from 1996 to 2002. Results: Strength declined signify scantly with age in all muscle groups except knee extensors. Age, hip flexor and abductor strength, and postural stability were signify scantly different in women who had fallen. Conclusions: Strength decline was not consistent across muscle groups. Women who were older, had less hip flexor or abductor strength, or less balance were more likely to have fallen. [ABSTRACT FROM AUTHOR]