Barry B. Shultz

Sensory cueing effects on maximal speed gait initiation in persons with Parkinson's disease and healthy elders

Researchers have suggested that sensory cues can improve gait initiation in persons with Parkinsons disease (PD); however, there is little research that documents the effects of sensory cues on gait initiation. The purpose of this study was to examine the effects of auditory and cutaneous sensory cues on maximal speed gait initiation in persons with PD and healthy elderly. Seven persons with PD of moderate severity (mean age=69 years) and seven age, gender, and height matched healthy elders participated. Temporal, kinematic and center of pressure (COP) data were recorded as participants performed eight trials within four randomly ordered conditions (no cue (NC), a single auditory cue (SA), repetitive auditory cues (RA), and repetitive cutaneous cues (RC)). In each condition, participants were instructed to perform each gait initiation trial at their maximal speed. In all conditions, persons with PD reacted more slowly and moved less far than did the matched elders. Relative to conditions with NCs, sensory cueing resulted in decreased double limb support (DLS), and increased COP displacement and velocity in both groups. However, in both groups, displacements and velocities of the swing limb and sacrum during the sensory-cued conditions were less than those during the NC condition. These results suggest that when movement speed is a primary goal, sensory cues may interfere with swing limb and body movement outcomes during the gait initiation task in both persons with PD and healthy elders.

Quantifying Physical Activity via Pedometry in Elementary Physical Education

PURPOSE The objective of this study was to determine a pedometer steps per minute standard for quantifying the lesson time that first- and second-grade physical education students spent in moderate to vigorous physical activity (MVPA). METHODS The sample was divided into validation (N = 246) and cross-validation (N = 123) samples using the holdout technique. Using the criterion test model, steps per minute cut points were empirically and judgmentally determined. C-SOFIT systematic observation was the criterion instrument and pedometry was the predictor instrument. Data were collected from 45 physical education lessons implemented in six schools. The three-step analytic procedure of computing mastery/nonmastery outcome probabilities, phi coefficients, and error proportions was used to determine the optimal steps per minute cut point for quantifying 33.33% of the physical education lesson time engaged in MVPA within a 30 class. RESULTS Steps per minute was highly correlated with observation (r = 0.74-0.86, P < 0.0001). Five steps per minute scores that were accurate indicators of 33.33% of the class time engaged in MVPA in the validation sample were accurate indicators of steps per minute in the cross-validation sample. The optimal steps per minute cut point ranged from 60.00 to 63.00, which is equivalent to 1800-1890 steps in a 30-min physical education class. CONCLUSION Data supports the use of pedometry steps per minute values as an accurate indicator of MVPA. Pedometry demonstrates promise as a viable large-scale surveillance instrument for measuring MVPA in physical education.

Daughters and Mothers Exercising Together: Effects of Home- and Community-Based Programs.

PURPOSE This pilot study compares the effectiveness of home- and community-based physical activity interventions that target mothers and daughters to increase physical activity and improve health-related fitness. METHODS Mothers (45.18 +/- 7.49 yr) and daughters (15.41 +/- 1.33 yr) were randomly assigned to a community-based (CB) (N = 20 participants) or home-based (HB) (N = 14 participants) program. CB participants attended three instructor-led sessions per week for 12 wk. HB participants were asked to participate in 3 sessions per week for 12 wk in a program similar to the CB program. The main difference between the programs was that CB activities were completed at a fitness facility within a university and HB activities were completed in or near the home. Before and after the intervention, changes in health-related fitness and physical activity were assessed. A series of 2 (group assignment) x 2 (time) ANOVAs were conducted to assess changes separately for mothers and daughters. RESULTS CB participants attended 77% of the sessions, and none of the pairs dropped out. HB participants completed 70% of the recommended sessions, and three pairs dropped out. Mothers and daughters in both groups significantly increased their participation in aerobic, muscular strength, and flexibility activities (P = 0.02 to 0.000). Daughters in both groups significantly improved their muscular endurance (sit-ups,P = 0.000). Mothers in both groups improved their muscular strength (push-ups, P = 0.003), muscular endurance (sit-ups, P = 0.000), flexibility (sit-and-reach, P = 0.008), and aerobic capacity (1-mile walk, P = 0.002). Positive changes in diastolic blood pressure also occurred (P = 0.008). CONCLUSION Mothers and daughters responded positively to CB and HB physical activity programs. Home-based physical activity programming is a cost-effective means to increase physical activity and improve health-related fitness in these groups.

Explaining Long-Term Exercise Adherence in Women Who Complete a Structured Exercise Program

The purpose of this study was to qualitatively examine factors related to physical activity adherence to understand why women continue to participate in long-term exercise after completing a structured exercise program. Data were collected from focus groups, interviews, and e-mails, and analysis used grounded theory. The central category related to physical activity adherence was self-worth. Motivation, activity enjoyment, priorities, body image, ability to access support, and self-regulation skills had an impact on the self-worth of nonadherers and adherers. Women must value themselves enough to continue to participate in physical activity once they start. Exercise and fitness professionals are encouraged to use strategies to increase self-worth and long-term adherence to physical activity. Some recommended strategies include (a) increasing motivation and enjoyment relative to activity, (b) making activity a high priority in a womans life, (c) improving or deemphasizing body image, (d) increasing a womans ability to access support, and (e) facilitating the use of self-regulation strategies. This study is the first to examine qualitative perspectives of exercise adherence among women who completed a structured exercise program. Several concepts related to adherence presented in the quantitative literature are confirmed and enhanced in this study.

Cardiorespiratory Fitness and Coronary Heart Disease Risk Factors The LDS Hospital Fitness Institute Cohort

BackgroundCardiorespiratory fitness is favorably associated with most modifiable coronary heart disease (CHD) risk factors. Findings are limited, however, by few data for women, persons with existing CHD, and low-risk populations. In the present study, we described cross-sectional associations between cardiorespiratory fitness and CHD risk factors in a large cohort of middle-aged men and women, of whom the majority were LDS Church members (Mormons), with and without existing CHD. Methods and ResultsComprehensive health examinations were performed on 3232 men (age 45.9±10.8 years) and 1128 women (age 43.8±12.8 years) between 1975 and 1997. Maximal treadmill exercise testing was used to categorize those with (12% of the men and 10% of the women) and those without CHD into age- and sex-specific cardiorespiratory fitness quintiles. After adjustments for age, body fat, smoking status, and family history of CHD, favorable associations were observed between fitness and most CHD risk factors among men and women, regardless of CHD status. ConclusionsThese data indicate that enhanced levels of cardiorespiratory fitness may confer resistance to elevations in CHD risk factors even in a low-risk sample of middle-aged men and women. Furthermore, these findings reinforce current public health recommendations that advocate increased national levels of physical activity and cardiorespiratory fitness for primary and secondary CHD prevention.

Norms for the Wingate Anaerobic Test with Comparison to Another Similar Test

This study was undertaken in order to develop norms for the Wingate test for physically active young men and women, and also to compare mean power measures obtained from the Wingate test with those obtained from another similar cycle ergometer test. A total of 112 males and 74 females aged 18 to 28 years comprised the subject pool. Data collected from the Wingate test included mean power for 30 s, peak power for 5 s, and a percent fatigue index. Data from the second test (Katch test) included mean power for both 30 s and 40 s. Percentile norms and descriptive statistics were generated as were multiple regression equations for prediction of mean power between the two different tests. Correlations between the two tests ranged from .66 to .87. Comparisons among data derived from this study and those reported for other athletic groups are also given.

Lumbar segmental mobility disorders: comparison of two methods of defining abnormal displacement kinematics in a cohort of patients with non-specific mechanical low back pain

BackgroundLumbar segmental rigidity (LSR) and lumbar segmental instability (LSI) are believed to be associated with low back pain (LBP), and identification of these disorders is believed to be useful for directing intervention choices. Previous studies have focussed on lumbar segmental rotation and translation, but have used widely varying methodologies. Cut-off points for the diagnosis of LSR & LSI are largely arbitrary. Prevalence of these lumbar segmental mobility disorders (LSMDs) in a non-surgical, primary care LBP population has not been established.MethodsA cohort of 138 consecutive patients with recurrent or chronic low back pain (RCLBP) were recruited in this prospective, pragmatic, multi-centre study. Consenting patients completed pain and disability rating instruments, and were referred for flexion-extension radiographs. Sagittal angular rotation and sagittal translation of each lumbar spinal motion segment was measured from the radiographs, and compared to a reference range derived from a study of 30 asymptomatic volunteers. In order to define reference intervals for normal motion, and define LSR and LSI, we approached the kinematic data using two different models. The first model used a conventional Gaussian definition, with motion beyond two standard deviations (2sd) from the reference mean at each segment considered diagnostic of rotational LSMD and translational LSMD. The second model used a novel normalised within-subjects approach, based on mean normalised contribution-to-total-lumbar-motion. An LSMD was then defined as present in any segment that contributed motion beyond 2sd from the reference mean contribution-to-normalised-total-lumbar-motion. We described reference intervals for normal segmental mobility, prevalence of LSMDs under each model, and the association of LSMDs with pain and disability.ResultsWith the exception of the conventional Gaussian definition of rotational LSI, LSMDs were found in statistically significant prevalences in patients with RCLBP. Prevalences at both the segmental and patient level were generally higher using the normalised within-subjects model (2.8 to 16.8% of segments; 23.3 to 35.5% of individuals) compared to the conventional Gaussian model (0 to 15.8%; 4.7 to 19.6%). LSMDs are associated with presence of LBP, however LSMDs do not appear to be strongly associated with higher levels of pain or disability compared to other forms of non-specific LBP.ConclusionLSMDs are a valid means of defining sub-groups within non-specific LBP, in a conservative care population of patients with RCLBP. Prevalence was higher using the normalised within-subjects contribution-to-total-lumbar-motion approach.

Does Augmented Feedback from Pedometers Increase Adults' Walking Behavior?

This study investigated whether feedback from pedometers motivated adults to increase their walking behavior. Participants (n = 26) were enrolled in one of two 8-wk. “Walking for Fitness” classes. The study used a crossover design, such that Group 1 wore pedometers for the first 3 weeks (Feedback Condition) and sealed “disguised” pedometers for the last 3 weeks (No-feedback Condition). The order of feedback was reversed for Group 2. Analysis indicated that (a) neither group increased their walking behavior significantly over time and, (b) interactions between groups were not significant at Week 3 or 6, indicating that groups did not respond differently to feedback from the pedometers. If a motivational effect from pedometers exists, it may be small, dissipate before 3 wk., only work in combination with goal setting, or only motivate certain types of individuals.

Bone mineral density of olympic-level female winter sport athletes.

PURPOSE To compare areal bone mineral density (aBMD) of female winter sport athletes to healthy controls of similar age and body mass index (BMI). METHODS Areal BMD (g x cm(-2)) of the whole body, lumbar spine (L2-L4), and right proximal femur were assessed by dual energy x-ray absorptiometry in athletes (N = 40; age: 26.1 +/- 5.7 yr; ht: 165.6 +/- 0.1 cm; wt: 63.0 +/- 6.5 kg; BMI: 23.0 +/- 1.9 kg x m(-2)) involved in speed skating (N = 9), snowboarding (N = 13), freestyle skiing (N = 3), biathlon (N = 8), bobsleigh, skeleton, luge (N = 7), and controls (N = 21; age: 26.0 +/- 5.1 yr; ht: 165.8 +/- 0.1 cm; wt: 62.8 +/- 5.9 kg; BMI: 22.9 +/- 1.3 kg x m(-2)). RESULTS Using independent t-tests, athletes had lower fat mass, percent body fat, and higher lean mass than controls (P < 0.001). Areal BMD was higher in athletes than controls for all skeletal sites (P </= 0.007). With lean tissue mass as a covariate (ANCOVA), differences in aBMD remained significant for most skeletal sites (P </= 0.016). Menstrual history, mean daily calcium intake, and oral contraceptive use were not associated with aBMD in the athletic group. CONCLUSION Results show that female winter sport athletes have greater aBMD compared with controls of similar age and BMI. Most aBMD differences remained significant after adjusting for lean tissue mass, and athletes with a history of oligo- and/or amenorrhea had similar aBMD than their eumenorrheic counterparts. This is the first study to examine aBMD in winter sport athletes. The results support the hypothesis that the loading characteristics of intense winter sport participation have osteogenic potential.

The US National Rugby Team: A Physiological and Anthropometric Assessment

In brief: We studied the physiological and anthropometric characteristics of 20 players who were members of the US national rugby team. Forwards were compared with back-line players, and these athletes were compared with other rugby players and other elite intermittent-sport athletes. The forwards were taller and heavier than the back-line players, had greater lean body weight, a higher percent body fat, greater gross anaerobic power and capacity, but similar aerobic capacities. Rugby players overall were slightly older and leaner than other intermittent-sport athletes. Their aerobic fitness was similar to that of professional basketball, football, and baseball players but lower than that of professional soccer players and national representative ice hockey players.