, 22% had a postsecondary education, 41% had a bachelor’s degree, and the remaining 21% had a higher (master’s or doctorate) level of education. All reported not having any physically debilitating condition. Measures Using a correlational study design, we administered questionnaires online to assess
Leehu Zysberg and Rotem Hemmel
Denine Ellis, Ervin Sejdic, Karl Zabjek and Tom Chau
The strength of time-dependent correlations known as stride interval (SI) dynamics has been proposed as an indicator of neurologically healthy gait. Most recently, it has been hypothesized that these dynamics may be necessary for gait efficiency although the supporting evidence to date is scant. The current study examines over-ground SI dynamics, and their relationship with the cost of walking and physical activity levels in neurologically healthy children aged nine to 15 years. Twenty participants completed a single experimental session consisting of three phases: 10 min resting, 15 min walking and 10 min recovery. The scaling exponent (α) was used to characterize SI dynamics while net energy cost was measured using a portable metabolic cart, and physical activity levels were determined based on a 7-day recall questionnaire. No significant linear relationships were found between a and the net energy cost measures (r < .07; p > .25) or between α and physical activity levels (r = .01, p = .62). However, there was a marked reduction in the variance of α as activity levels increased. Over-ground stride dynamics do not appear to directly reflect energy conservation of gait in neurologically healthy youth. However, the reduction in the variance of α with increasing physical activity suggests a potential exercise-moderated convergence toward a level of stride interval persistence for able-bodied youth reported in the literature. This latter finding warrants further investigation.
J.A. McCubbin, P. Rintala and G.C. Frey
John H. Hollman, Kimberly E. Kolbeck, Jamie L. Hitchcock, Jonathan W. Koverman and David A. Krause
Hip-muscle weakness might be associated with impaired biomechanics and postures that contribute to lower extremity injuries.
To examine relationships between hip-muscle strength, Q angle, and foot pronation.
33 healthy adults.
Main Outcome Measures:
Maximal isometric hip abduction (Abd), adduction (Add), external-rotation (ER) and internal-rotation (IR) strength; Q angle of the knee; and longitudinal arch angle of the foot. We analyzed Pearson product– moment (r) correlation coefficients between the Abd/Add and ER/IR force ratios, Q angle, and longitudinal arch angle.
The hip Abd/Add force ratio was correlated with longitudinal arch angle (r = .35, P = .025).
Reduced strength of the hip abductors relative to adductors is associated with increased pronation at the foot. Clinicians should be aware of this relationship when examining patients with lower extremity impairments.
Robert English, Mary Brannock, Wan Ting Chik, Laura S. Eastwood and Tim Uhl
Lower extremity functional testing assesses strength, power, and neuro-muscular control. There are only moderate correlations between distance hopped and isokinetic strength measures.
Determine if incorporating body weight in the single-leg hop for distance increases the correlation to isokinetic measures.
30 healthy college students; 15 men and 15 women; ages 18 to 30 years.
Main Outcome Measures:
Isokinetic average peak torque and total work of quadriceps and hamstrings and single-leg hop work and distance.
Significant correlations include hop work to total-work knee extension (r = .89), average peak-torque knee extension (r = .88), distance hopped to total-work knee extension (r = .56) and average peak-torque knee extension (r = .63). Correlations involving hop work were greater than distance hopped (P < .05).
Use of body weight in the assessment of distance hopped provides better information about the patient’s lower extremity strength and ability than the distance hopped alone.
Athanasios Mouratidis, Maarten Vansteenkiste, Willy Lens and Georgios Sideridis
Based on self-determination theory (Deci & Ryan, 2000), an experimental study with middle school students participating in a physical education task and a correlational study with highly talented sport students investigated the motivating role of positive competence feedback on participants’ well-being, performance, and intention to participate. In Study 1, structural equation modeling favored the hypothesized motivational model, in which, after controlling for pretask perceived competence and competence valuation, feedback positively predicted competence satisfaction, which in turn predicted higher levels of vitality and greater intentions to participate, through the mediation of autonomous motivation. No effects on performance were found. Study 2 further showed that autonomous motivation mediated the relation between competence satisfaction and well-being, whereas amotivation mediated the negative relation between competence satisfaction and ill-being and rated performance. The discussion focuses on the motivational role of competence feedback in sports and physical education settings.
Kathleen Simpson, Beth Parker, Jeffrey Capizzi, Paul Thompson, Priscilla Clarkson, Patty Freedson and Linda Shannon Pescatello
Little information exists regarding the psychometric properties of question 8 (Q8) of the Paffenbarger Physical Activity Questionnaire (PPAQ) to assess exercise. Thus, we conducted 2 studies to assess the validity and test–retest reliability of Q8 among adults.
Study 1 participants (n = 419) were 44.1 ± 16.1 years of age. Validity was determined by comparing self-reported hr·d−1 in sedentary, light, moderate, and vigorous intensity physical activity (PA) and MET-hr·wk−1 on Q8 at baseline to accelerometer and health/fitness measurements using Spearman rank-order correlations. Study 2 participants (n = 217) were 44.7 ± 16.3 years of age and completed Q8 at baseline, 3 months, and 6 months. Test–retest reliability was determined using repeated measures analysis of covariance, intraclass correlations (ICCs), and standard error of the measurement (SEM).
Q8 displayed good criterion validity compared with accelerometer measurements (r = .102 to .200, P < .05) and predictive validity compared with health/fitness measurements (r = –.272 to .203, P < .05). No differences were observed in self-reported hr·d−1 in any of the PA categories at baseline, 3 months, and 6 months (ICC: 0.49 to 0.68; SEM: 1.0 to 2.0; P > .05), indicating good reliability.
Q8 demonstrates adequate criterion validity, acceptable predictive validity, and satisfactory test–retest reliability and can be used in conjunction with other components of the PPAQ to provide a complete representation of exercise.
Heather A. Starnes, Philip J. Troped, David B. Klenosky and Angela M. Doehring
To provide a synthesis of research on trails and physical activity from the public health, leisure sciences, urban planning, and transportation literatures.
A search of databases was conducted to identify studies published between 1980 and 2008.
52 studies were identified. The majority were cross-sectional (92%) and published after 1999 (77%). The evidence for the effects of trails on physical activity was mixed among 3 intervention and 5 correlational studies. Correlates of trail use were examined in 13 studies. Several demographic (eg, race, education, income) and environmental factors (eg, land-use mix and distance to trail) were related to trail use. Evidence from 31 descriptive studies identified several facilitators and barriers to trail use. Economic studies (n = 5) examining trails in terms of health or recreational outcomes found trails are cost-effective and produce significant economic benefits.
There is a growing body of evidence demonstrating important factors that should be considered in promoting trail use, yet the evidence for positive effects of trails on physical activity is limited. Further research is needed to evaluate the effects of trails on physical activity. In addition, trail studies that include children and youth, older adults, and racial and ethnic minorities are a research priority.
Rodrigo de Marche Baldon, Daniel Ferreira Moreira Lobato, Lívia Pinheiro Carvalho, Paloma Yan Lam Wun, Cátia Valéria Presotti and Fábio Viadanna Serrão
Recently, attention in sports has been given to eccentric hip-muscle function, both in preventing musculoskeletal injuries and improving performance.
To determine the key isokinetic variables of eccentric hip torque that predict the functional performance of women in the single-leg triple long jump (TLJ) and the timed 6-m single-leg hop (TH).
Within-subject correlational study.
32 healthy women age 18–25 y.
The participants performed 2 sets of 5 eccentric hip-abductor/adductor and lateral/medial-rotator isokinetic contractions (30°/s) and 3 attempts in the TLJ and TH.
Main Outcome Measurements:
The independent variables were the eccentric hip-abductor and –adductor and medial- and lateral-rotator isokinetic peak torque, normalized according to body mass (Nm/kg). The dependent variables were the longest distance achieved in the TLJ normalized according to body height and the shortest time spent during the execution of the TH.
The forward-stepwise-regression analysis showed that the combination of the eccentric hip lateral-rotator and -abductor isokinetic peak torque provided the most efficient estimate of both functional tests, explaining 65% of the TLJ variance (P < .00l) and 55% of the TH variance (P < .001).
Higher values for eccentric hip lateral-rotator and hip-abductor torques reflected better performance. Thus, the eccentric action of these muscles should be considered in the development of physical training programs that aim to increase functional performance.
Shogo Uota, Anh-Dung Nguyen, Naoko Aminaka and Yohei Shimokochi
Excessive knee valgus and tibial external rotation relative to the femur during weight bearing motions, such as jump-landing, reportedly increases the risk of developing chronic knee pain, such as patellofemoral pain. Excessive deviations from normal ranges of several static lower extremity alignment measures and dynamic hip motions may also increase the risks for patellofemoral pain.
To determine the relationship between lower extremity alignments and hip motions to frontal and transverse plane knee motions during double-leg landings.
Patients or Other Participants:
69 healthy, competitive athletes (27 men, 42 women; height, 166.5 ± 9.5 cm; weight, 61.3 ± 9.9 kg; age, 20.7 ± 1.0 y) participated in this study.
Prone and supine hip version, quadriceps angle, and tibiofemoral angle were measured. Frontal and transverse knee and hip angles at peak knee extensor moment during landing were calculated.
Main Outcome Measures:
2 separate stepwise multiple regression analyses were conducted to predict frontal and transverse plane knee motions using 4 static lower extremity alignment measures and hip motions.
Greater hip adduction and prone hip anteversion, and lesser hip internal rotation and supine hip anteversion, were related to greater knee valgus motions (R 2 = .475, P < .01). Greater hip adduction was related to greater knee external rotation (R 2 = .205, P < .01).
Some targeted static lower extremity alignments and hip motions are associated with frontal and transverse knee motions. However, stronger relationships of hip motions with knee motions than static lower extremity alignments provided evidence that improving hip movements may help improve patellofemoral pain in those with lower extremity malalignments.