of temporal consistency in a given task ( Ivry & Hazeltine, 1995 ). The source of this variability may be attributed to imprecision in the central timekeeper (or timekeepers) or to some delay in the implementation of this timing signal to produce an overt movement ( Repp, 2005 ; Wing, 2002 ). Wing
Victoria Galea, Robyn Traynor and Michael Pierrynowski
Kathye E. Light, Marie A. Reilly, Andrea L. Behrman and Waneen W. Spirduso
The purpose of this study was to examine the effect of practice on simple reaction time (RT), movement time (MT), and response consistency for two arm-reaching tasks of graded complexity in younger and older adults. Forty subjects, 20 younger adults (age range = 20–29 years) and 20 older adults (age range = 60–82 years), were randomly subdivided into practice and control groups. All subjects were pretested on each arm-reaching movement on Day 1. The practice groups practiced each task for 160 trials over 2 consecutive days while the control groups practiced a memory task and answered a health survey. All subjects were posttested on Day 3. The major finding was that practice reduced the simple RTs of older persons to the level of younger persons. MTs for both practice age groups were reduced, but the age differences in MT performance were maintained.
Paolo Menaspà, Franco M. Impellizzeri, Eric C. Haakonssen, David T. Martin and Chris R. Abbiss
To determine the consistency of commercially available devices used for measuring elevation gain in outdoor activities and sports.
Two separate observational validation studies were conducted. Garmin (Forerunner 310XT, Edge 500, Edge 750, and Edge 800; with and without elevation correction) and SRM (Power Control 7) devices were used to measure total elevation gain (TEG) over a 15.7-km mountain climb performed on 6 separate occasions (6 devices; study 1) and during a 138-km cycling event (164 devices; study 2).
TEG was significantly different between the Garmin and SRM devices (P < .05). The between-devices variability in TEG was lower when measured with the SRM than with the Garmin devices (study 1: 0.2% and 1.5%, respectively). The use of the Garmin elevation-correction option resulted in a 5–10% increase in the TEG.
While measurements of TEG were relatively consistent within each brand, the measurements differed between the SRM and Garmin devices by as much as 3%. Caution should be taken when comparing elevation-gain data recorded with different settings or with devices of different brands.
Francisco J. Vera-Garcia, Diego López-Plaza, Casto Juan-Recio and David Barbado
Stable and Unstable Sitting Test) and field settings (Biering-Sørensen Test, 3-Plane Core Strength Test, and Double-Leg Lowering Test). In addition, in order to avoid the potential bias caused by the low consistency of the variables on the correlational analysis, 25 , 26 the relative and absolute
Peter Wolf, Renate List, Thomas Ukelo, Christian Maiwald and Alex Stacoff
Before conclusions can be drawn with respect to the quality of adaptations in human gait, the day-to-day consistency of the variables of interest must be known. The present study estimated the day-to-day consistency of kinematic variables collected during barefoot walking and running. Sixteen healthy subjects performed two gait analysis sessions based on skin markers. Test sessions were at least 1 week apart. In total, 48 ranges of motion were monitored for the hip, knee, ankle, and midfoot joint. Based on differences between the repeated gait analysis sessions, the day-to-day consistency was estimated. It was found that the day-to-day consistency was of the magnitude of 3 to 4 degrees for almost all ranges of motion independently of the test condition, the investigated joints, or the cardinal body plane. It was concluded that future studies on effects of interventions or on the characterization of pathological versus normative gait should consider the provided values of day-to-day consistency to improve their interpretation and conclusions.
Ty B. Palmer, Jose G. Pineda and Rachel M. Durham
reporting lower reliability values for these variables. 3 , 11 Because the reliability values reported in several of these studies were for early (≤100 ms) RFD characteristics derived from lower knee joint angles (90 and 120°), 3 , 11 it remains unclear whether the consistency of these isometric squat
Justin P. Waxman, Randy J. Schmitz and Sandra J. Shultz
Hamstring stiffness (KHAM) and leg stiffness (KLEG) are commonly examined relative to athletic performance and injury risk. Given these may be modifiable, it is important to understand day-to-day variations inherent in these measures before use in training studies. In addition, the extent to which KHAM and KLEG measure similar active stiffness characteristics has not been established. We investigated the interday measurement consistency of KHAM and KLEG, and examined the extent to which KLEG predicted KHAM in 6 males and 9 females. KHAM was moderately consistent day-to-day (ICC2,5 = .71; SEM = 76.3 N·m–1), and 95% limits of agreement (95% LOA) revealed a systematic bias with considerable absolute measurement error (95% LOA = 89.6 ± 224.8 N·m–1). Day-to-day differences in procedural factors explained 59.4% of the variance in day-to-day differences in KHAM. Bilateral and unilateral KLEG was more consistent (ICC2,3 range = .87–.94; SEM range = 1.0–2.91 kN·m–1) with lower absolute error (95% LOA bilateral= –2.0 ± 10.3; left leg = –0.36 ± 3.82; right leg = –1.05 ± 3.61 kN·m–1). KLEG explained 44% of the variance in KHAM (P < .01). Findings suggest that procedural factors must be carefully controlled to yield consistent and precise KHAM measures. The ease and consistency of KLEG, and moderate correlation with KHAM, may steer clinicians toward KLEG when measuring lower-extremity stiffness for screening studies and monitoring the effectiveness of training interventions over time.
Yong “Tai” Wang, Konstantinos Dino Vrongistinos and Dali Xu
The purposes of this study were to examine the consistency of wheelchair athletes’ upper-limb kinematics in consecutive propulsive cycles and to investigate the relationship between the maximum angular velocities of the upper arm and forearm and the consistency of the upper-limb kinematical pattern. Eleven elite international wheelchair racers propelled their own chairs on a roller while performing maximum speeds during wheelchair propulsion. A Qualisys motion analysis system was used to film the wheelchair propulsive cycles. Six reflective markers placed on the right shoulder, elbow, wrist joints, metacarpal, wheel axis, and wheel were automatically digitized. The deviations in cycle time, upper-arm and forearm angles, and angular velocities among these propulsive cycles were analyzed. The results demonstrated that in the consecutive cycles of wheelchair propulsion the increased maximum angular velocity may lead to increased variability in the upper-limb angular kinematics. It is speculated that this increased variability may be important for the distribution of load on different upper-extremity muscles to avoid the fatigue during wheelchair racing.
Jessica L. Unick, Kelley Strohacker, George D. Papandonatos, David Williams, Kevin C. O’Leary, Leah Dorfman, Katie Becofsky and Rena R. Wing
This study examined whether inactive, overweight/obese women experience consistent affective responses to moderate-intensity exercise. Twenty-eight women participated in 3 identical (same treadmill grade and speed within a subject) 30-min exercise sessions. The Feeling Scale (FS), Positive and Negative Affect Schedule and Subjective Exercise Experience Scale were administered pre- and postexercise and FS was also administered every 5 min during exercise. All measures exhibited less than optimal agreement in pre-to-postexercise change within an individual across the 3 sessions (ICCs = 0.02–0.60), even after controlling for within-subject variations in heart rate. Only FS exhibited “good” consistency when controlling for preexercise values (ICC = 0.72). However, the mean FS score during exercise was highly consistent within an individual (ICC = 0.83). Thus, an individual’s affective response to an exercise session does not provide reliable information about how they will respond to subsequent exercise sessions. Taking the average of FS measurements during exercise may yield more consistent findings.
Peter R. Giacobbi Jr. and Robert S. Weinberg
The purposes of the present investigation were to examine the coping responses of different subgroups of athletes (e.g., high and low trait anxious athletes), and to assess the consistency of athlete’s coping behaviors across situations. Two-hundred and seventy-three athletes completed the Sport Anxiety Scale (SAS) by Smith, Smoll, & Schutz (1990) and coping assessments in trait and state versions of the sport adapted COPE (MCOPE) by Crocker and Graham (1995). The state coping measures assessed coping responses of situations for which the athletes actually experienced. The results of three separate, doubly multivariate, repeated measures, MANOVA’s showed that high trait anxious athletes responded to stressful situations using different coping behaviors (e.g., denial, wishful thinking, and self-blame) than the low trait anxious athletes. In addition, coping appears to be more stable than situationally variable as Pearson correlational coefficients computed between the three measures ranged from 0.53 to 0.80. The results are discussed with regard to theoretical, research, and applied issues.