The Effect of Visual Environmental Distraction on Gait Performance in Children.

PURPOSE: Identify the effect of visual distraction on gait parameters in children and describe the role of walking experience (WE) in the management of visual distraction. METHODS: Forty-two typically developing children, mean age 43.2 months (SD = 22.9) participated and were divided into three groups according to WE: early walkers (6-11 months of WE), preschool walkers (12-37 months of WE), and experienced walkers (38-79 months of WE). Gait parameters measured under two conditions (no visual distraction and with visual distraction) included: velocity, step length, step width, and double limb support percentage (DLS%) of gait cycle. Multivariate analysis of variance assessed differences in gait between groups (effect of WE) and within groups (effect of condition). RESULTS: Significant main effects of WE group F(8,74) = 5.300, p ≤.001 and visual distraction condition F(4,36) = 2.586, p = 0.053 were found. Visual environmental distraction significantly affected gait performance in children regardless of walking experience. Velocity decreased from 110.04 to 97.73 cm/sec (p = 0.003) while DLS% of gait cycle increased from 18.29% to 20.39% (p = 0.025). CONCLUSIONS: Results suggest physical therapists need to consider attentional requirements when assessing gait; even in children with more WE. If attention to task is a limiting factor for performance or learning of a motor task, it may need to be addressed directly as part of the treatment plan.

Interdevice reliability and validity assessment of the Nicholas Hand-Held Dynamometer.

The Nicholas Hand-Held Dynamometer (HHD) has been shown to have excellent interday and intraday reliability when using the same HHD. Since clinics may have more than one HHD with which to evaluate patients, it would be of value to know if two identical HHDs measure the same variable consistently. The purpose of this investigation was to assess interdevice reliability of the Nicholas HHD as well as to determine its validity. Thirty healthy female subjects between the ages of 20 and 56 years (mean age = 28.4) were tested for hamstring strength. Three measurements of maximum hamstring contractions were obtained using the first HHD (Device A). The average of these three measurements was compared with the average of three measurements obtained after a brief rest using a second HHD (Device B). Measurements from the two HHDs were also compared with measurements obtained from a Kin-Com isokinetic dynamometer. The Kin-Com measurements were used as criteria to determine validity of the HHD. An intraclass correlation coefficient (ICC) calculated to determine reliability between the two HHDs was low (ICC = .58). Pearson product-moment correlation coefficients were calculated between the Kin-Com and each of the two HHDs. These values were .85 and .83 for Device A and B, respectively. Analysis of variance showed no significant difference between the Kin-Com and Device A but a significant difference between the Kin-Com and Device B (p < .001). Measurements obtained from two identical HHDs may be significantly different and should not be compared.

Cross-validation of height and gender estimations of femoral condyle width in osteochondral allografts.

A cross-validation study was conducted on the estimation of femoral condyle width from height and gender. An equation was published in 1989 for estimation of femoral condyle width using in vivo measurements of femoral condyle width from radiographs. Further cross-validation evidence for this equation is reported using in vitro measurements from 27 cadavers. The data indicated a high correlation (r = 0.85) between actual and estimated femoral condyle width and an acceptable standard error of estimate (range, 4.48-4.29 mm). It was concluded that the published equation which uses height and gender to form an estimate of femoral condyle width has acceptable validity and is a useful tool in the selection process of donors for osteochondral allografts.

Eccentric/Concentric torque deficits in the quadriceps muscle.

The purpose of the present investigation was to estimate the percentage of asymptomatic subjects who demonstrate an eccentric/concentric torque deficit in leg extension. One hundred and five subjects with a mean age of 23.51 were tested on the KIN-COM(R) dynamometer for maximum eccentric and concentric torque during leg extension using an 80 degrees range of motion at 50 degrees /sec velocity. The subjects were categorized as demonstrating a deficit if at any point in the range of motion the eccentric torque was 85% or less of the corresponding concentric torque. The results revealed that 35-54% of the subjects, depending upon sex or leg tested, demonstrated a deficit. These results suggest that many asymptomatic individuals possess an eccentric/concentric torque deficit. These findings question the validity of previous clinical research indicating that patients with anterior knee pain tend to possess an eccentric/concentric torque deficit and that correction of the deficit alleviates the pain. J Orthop Sports Phys Ther 1989;11(4):142-145.