The effects of direction and speed on treadmill walking in typically developing children.

BACKGROUND: Backward walking and fast walking have distinctive gait patterns in adults; however, there is minimal literature describing these gait modifications in typically developing children. Additionally, most of previous research focused on overground backward walking, but not on a treadmill. RESEARCH QUESTION: How do typically developing children adapt their gait patterns, including spatiotemporal parameters, joint kinematics, and muscle activation, to changes in direction and speed during treadmill walking? METHODS: We recruited 19 children (10 M/9 F) aged 6-12 years. Treadmill conditions included forward and backward walking at three speeds: slow (75 % of normal speed), normal speed, and fast (125 % of normal speed). Subjects completed a 2-minute trial under each condition. Spatiotemporal, kinematic, kinetic and electromyography data were collected and analyzed. Correlations between forward and time-reversed backward walking were calculated for joint angles and vertical ground reaction force. RESULTS: During backward walking, children (a) decreased step lengths and increased step widths and foot clearance, (b) decreased peak hip and knee flexion and increased peak ankle dorsiflexion, and (c) increased muscle activity at the vastus lateralis, rectus femoris, and tibialis anterior. At faster speeds, children increased step lengths and inconsistently increased overall muscle activity. Both the hip and knee showed high correlation between forward and time-reversed backward walking, while correlation at the ankle was low. SIGNIFICANCE: Overall, children adapt their gait to changes in direction and speed of treadmill walking in similar ways to adults. However, notable differences emerged in that children limited their ankle range of motion. Our results suggest that, while many aspects of gait are mature enough by this age to adapt to backward walking on a treadmill, neuromuscular control at the ankle may still be lacking in children while walking backward on a treadmill.

Neuromuscular response to a single session of whole-body vibration in children with cerebral palsy: A pilot study.

BACKGROUND: Whole-body vibration (WBV) is a relative new intervention paradigm that could reduce spasticity and improve motor function in children with cerebral palsy (CP). We investigated neuromuscular response to a single session of side-alternating WBV with different amplitudes in children with CP. METHODS: Ten children with spastic CP aged 7-17 years at GMFCS level I-III participated in this pilot study. Participants received two sessions of side-alternating WBV with the same frequency (20 Hz) but different amplitudes (low-amplitude: 1 mm and high-amplitude: 2 mm). Each session included six sets of 90 s of WBV and 90 s of rest. Before and after each WBV session, we used (a) the modified Ashworth scale to evaluate the spasticity of the participants' leg muscles, (b) a quiet standing task to analyze center-of-pressure (CoP) pattern and postural control, and (c) overground walking trials to assess spatiotemporal gait parameters and joint range-of-motion (RoM). RESULTS: Both WBV sessions similarly reduced the spasticity of the ankle plantarflexors, improved long-range correlation of CoP profile during standing, and reduced muscle activity of tibialis anterior during walking. The high-amplitude WBV further increased ankle RoM during walking. CONCLUSIONS: This study demonstrates that a single session of WBV with either a low or a high amplitude can reduce spasticity, enhance standing posture, and improve gait patterns in children with CP. It suggests that low-amplitude WBV may induce similar neuromuscular response as high-amplitude WBV in children with spastic CP and can provide positive outcomes for those who are not able to tolerate stronger vibration.

Improvement in Overground Walking After Treadmill-Based Gait Training in a Child With Agenesis of the Corpus Callosum.

BACKGROUND: Agenesis of the corpus callosum (ACC) is a rare congenital brain defect that produces a wide variety of cognitive and motor impairments. Literature regarding the response of pediatric populations with ACC to physical rehabilitation is scarce. Treadmill-based gait training (TT) has been shown to improve walking ability in some pediatric populations but has not been investigated in children with ACC. OBJECTIVE: The purpose of this study was to investigate the effect of a novel treadmill intervention paradigm on the gait parameters of a child with ACC. DESIGN: A single-participant design with 2 phases was used. METHODS: The settings were the participant's home and the laboratory. The participant was a 13-year-old girl who had ACC and cortical visual impairment and who ambulated independently using a reverse walker for household and short community distances. A home-based TT intervention (2 phases of 3 months of training over 6 months) was implemented, and a laboratory-based gait analysis was conducted at 4 time points: baseline, after each of the 2 training phases, and 3 months after the cessation of training. The intervention consisted of weekly bouts of TT. Phase I incorporated forward, backward, and incline walking for 15 minutes each; in phase II, this protocol was continued, but short-burst interval training for 10 minutes was added. Data collected at each laboratory visit included spatiotemporal parameters and kinematics (joint angles) during overground and treadmill walking. RESULTS: After both phases of training, increased step length, decreased step width, and foot progression angle and decreased variability of most spatiotemporal parameters were observed for the participant. Further, after phase II, increased peak extension at the hip, knee, and ankle, decreased crouched gait, and improved minimum foot clearance during overground walking were observed. Most gait improvements were retained for 3 months after the cessation of the intervention. LIMITATIONS: The small sample size of this study and wide variety of presentations within individuals with ACC limit the generalizability of our findings. CONCLUSIONS: TT may be a safe and effective treatment paradigm for children with ACC. Future research should investigate the effect of intervention dosage on gait improvements and generalization in individuals with ACC.

Variability of spatiotemporal gait parameters in children with and without Down syndrome during treadmill walking.

BACKGROUND: Increasing walking speed and including bilateral external ankle load have been shown to improve aspects of the gait pattern of children with Down syndrome (DS). However, it is unknown if speed and ankle load improves the cycle-to-cycle variability in a similar way. RESEARCH QUESTION: How do changes of walking speed and external ankle load impact spatiotemporal variability during treadmill walking in children with and without DS? METHODS: Thirteen children with DS (aged 7-10 years) and thirteen age- and sex-matched typically developing (TD) children participated in this study. Subjects completed two bouts of 60-second treadmill walking at two different speeds (slow and fast) and two load conditions (no load and ankle load equaling to 2% bodyweight at each side). Kinematic data was captured using a Vicon motion capture system. Mean and coefficient of variance of spatiotemporal gait variables were calculated and compared between children with and without DS. RESULTS AND SIGNIFICANCE: Across all conditions, the DS group took shorter and wider steps than the TD group, but walked with a similar swing percentage, double support percentage, and foot rotation angle. Further, the DS group demonstrated greater variability of all spatiotemporal parameters, except for step width and foot rotation angle. Our results indicated that children with DS can modulate their spatiotemporal gait pattern accordingly like their TD peers when walking faster on a treadmill and/or with an external ankle load. Smaller step width variability in the DS group suggests that mediolateral stability may be prioritized during treadmill walking to safely navigate the treadmill and complete walking tasks. Similar temporal parameters but distinct spatial parameters in the DS group suggest that they may have developed similar rhythmic control but are confined by their spatial movement limitations.

Feasibility of event-related potential methodology to evaluate changes in cortical processing after rehabilitation in children with cerebral palsy: a pilot study.

This study examined the feasibility of using event-related potentials (ERPs) to measure changes in cortical processing following an established rehabilitative intervention (constraint-induced movement therapy, CIMT) for children with cerebral palsy (CP). Sixteen participants with a diagnosis of hemiparetic CP, with a median age of 6 years, were assessed pre and immediately post CIMT and at 6-month follow-up, using a picture-word match/mismatch discrimination task and standard neurobehavioral measures. Intervention effects were evident in improved performance on behavioral tests of sensory and motor function and the increased mean ERP amplitude of the N400 match/mismatch response on the side ipsilateral to the lesion. These effects were maintained 6 months after the intervention. No such changes were observed on the side contralateral to the lesion. This research suggests that ERPs can measure rehabilitation-induced changes in neural function in children with CP.