Elizabeth A. Holbrook

Validity and reliability of omron pedometers for prescribed and self-paced walking

PURPOSE The purpose of this study was to examine the validity and reliability evidence for the Omron Healthcare HJ-151 and HJ-720ITC pedometers for prescribed and self-paced walking. METHODS A total of 47 adults (24 males, 23 females; age = 24 +/- 4.4 yr.; body mass index = 25.7 +/- 4.2 kg x m(-2)) participated in this study. Under prescribed walking conditions, 34 participants completed three randomized 100-m walking trials through a range of scripted walking speeds (slow, moderate, and very brisk) for each pedometer model. Under self-paced walking conditions, 31 participants completed one 1-mile walk on a standardized course for each model. HJ-151 pedometers were chosen at random from a pool of 54 devices and were worn along the waistband at the right hip, the left hip, and the midback, whereas HJ-720ITC pedometers were chosen from a pool of 24 devices and incorporated right pocket, left pocket, and backpack positions in addition to the three waist-mounted sites. Absolute percent error (APE) scores were calculated to examine pedometer accuracy between actual steps (a criterion measure) and pedometer-determined steps. Coefficient of variation (CoV) was computed to describe interdevice reliability. RESULTS With the exception of the HJ-720ITC at the backpack position in the prescribed walking setting (mean APE = 3.4%), the HJ-151 and the HJ-720ITC accurately reported step counts under prescribed and self-paced conditions (all APE values <3.0%). Moreover, interdevice reliability evidence was established for the HJ-151 and the HJ-720ITC under prescribed and self-paced conditions (all CoV values <2.1%). CONCLUSIONS The Omron HJ-151 and HJ-720ITC pedometers demonstrated validity and reliability at various mounting positions under prescribed and self-paced walking conditions with both healthy and overweight adults.

Influence of age on step activity patterns in children with cerebral palsy and typically developing children.

OBJECTIVE To document the influence of age on step activity patterns in children with cerebral palsy (CP) and typically developing (TD) children. DESIGN Cross-sectional. SETTING All step activity data were collected in free-living environments. PARTICIPANTS Children with CP (n=27; age, 4-18y; 22 boys, 5 girls; Gross Motor Function Classification System levels I and II) and 27 age- and sex-matched TD children were recruited through public advertisements and contacts with local clinicians. CP and TD participants were stratified into younger (<10y; n=14) and older (10-18y; n=13) age groups. INTERVENTION Daily step activity was monitored using a step activity monitor that was individually programmed to account for the gait characteristics of each participant. Step activity data were collected in 1-minute epochs during waking hours on 3 weekdays and 1 weekend day. Stored data were analyzed to yield average values of daily step activity, percentage of inactive time (0 steps) over the entire day, and percentage of total daily active time spent in low step activity (1-15 steps/min), medium step activity (16-40 steps/min), and high step activity (>40 steps/min). MAIN OUTCOME MEASURES Daily step activity, percentage of inactive time, and percentage of active time spent in low-, moderate-, and high-intensity step activity. RESULTS A significant (P<.05) interaction was observed between age (younger, older) and condition (CP, TD) for daily step activity, percentage of inactive time, and percentage of active time spent in low- and high-intensity step activity. The main effect of age was significant for each physical activity measure except for relative high-intensity step activity, and the main effect of condition was significant for all physical activity measures. Follow-up analyses (P<.025) revealed that older children with CP took fewer daily steps and displayed higher relative levels of inactivity and low-intensity activity and lower relative levels of high-intensity activity compared with older TD children. Older children with CP also exhibited lower daily step activity, demonstrated higher relative levels of inactivity and low-intensity activity, and displayed lower relative levels of moderate-intensity activity compared with younger children with CP. CONCLUSIONS Compared with younger children with CP and age- and sex-matched TD youth, older youth with CP generally displayed step activity patterns typified by lower levels of physical activity and a greater degree of inactivity. These findings highlight the need to provide multiple opportunities for adolescents with CP to engage in a variety of physical activities that are appropriate to their needs, abilities, and preferences and that can aid in maintaining functional mobility, health, and quality of life.