Lower-Body Positive Pressure Treadmill Training for Pediatric Gait Disorders: A Scoping Review

The purpose of this scoping review was to examine the literature on the use of anti-gravity treadmills and its effects on lower-limb motor functions in children and adolescents with locomotor impairments. Method: Four databases (MEDLINE, CINAHL, Embase, Web of Science) were searched for articles from inception to August 2021. Inclusion criteria were: (1) experimental or quasi-experimental studies using anti-gravity training as the primary intervention; (2) studies conducted in pediatric participants; (3) articles reporting outcomes related to lower-limb functions; and (4) studies published in French or English. Results: Fifteen articles were included in the review. Studies included children and adolescents aged 4–18 years with locomotor impairments. Intervention duration ranged from 2 to 12 weeks, with 2–5 sessions per week. Included studies reported that anti-gravity training induces improvements in muscle strength, balance, spatiotemporal gait parameters, and walking endurance in children with locomotor impairments. Conclusion: This review provides relevant information about interventions, outcomes and limits associated with anti-gravity training in pediatrics. Overall, anti-gravity treadmill training could be viewed as a valuable training modality, specifically for children with cerebral palsy. However, a more precise and comprehensive description of anti-gravity training protocols would be useful.

Lower Body Positive Pressure Treadmill Training for Pediatric Gait Disorders: A Scoping Review

The purpose of this scoping review was to examine the literature on the use of anti-gravity treadmill and its effects on lower limb motor functions in children and adolescents with locomotor impairments. Four databases (MEDLINE, CINAHL, Embase, Web of Science) were searched for articles from inception to August 2021. Inclusion criteria were: (1) experimental or quasi-experimental studies using the anti-gravity training as the primary intervention; (2) studies conducted in paediatricpediatric participants; (3) articles reporting outcomes related to the lower limb functions; and (4) studies published in French or English. Fifteen articles were included in the review. Studies included children and adolescents aged 4–18 years with locomotor impairments. The intervention duration was ranged from 2 and to 12 weeks, with 2-5 sessions per week. Included studies showed reported that anti-gravity training induces improvements in muscle strength, balance, spatiotemporal gait parameters, and walking endurance in children with locomotor impairments. This review provides relevant information about the modalities, outcomes and limits associated with the anti-gravity training protocol reported in the literature. Overall, the anti-gravity treadmill training could be viewed as a valuable training modality for children with cerebral palsy. However, more precise, and comprehensive description of anti-gravity rehabilitation protocols would be useful.

Use of Pressure-Measuring Insoles to Characterize Gait Parameters in Simulated Reduced-Gravity Conditions

Prior researchers have observed the effect of simulated reduced-gravity exercise. However, the extent to which lower-body positive-pressure treadmill (LBPPT) walking alters kinematic gait characteristics is not well understood. The purpose of the study was to investigate the effect of LBPPT walking on selected gait parameters in simulated reduced-gravity conditions. Twenty-nine college-aged volunteers participated in this cross-sectional study. Participants wore pressure-measuring insoles (Medilogic GmBH, Schönefeld, Germany) and completed three 3.5-min walking trials on the LBPPT (AlterG, Inc., Fremont, CA, USA) at 100% (normal gravity) as well as reduced-gravity conditions of 40% and 20% body weight (BW). The resulting insole data were analyzed to calculate center of pressure (COP) variables: COP path length and width and stance time. The results showed that 100% BW condition was significantly different from both the 40% and 20% BW conditions, p < 0.05. There were no significant differences observed between the 40% and 20% BW conditions for COP path length and width. Conversely, stance time significantly differed between the 40% and 20% BW conditions. The findings of this study may prove beneficial for clinicians as they develop rehabilitation strategies to effectively unload the individual’s body weight to perform safe exercises.

Temporary application of lower body positive pressure improves intracranial velocities in symptomatic acute carotid occlusion or tight stenosis: A pilot study

Background Patients with isolated cervical carotid artery occlusion not eligible to recanalization therapies but with compromised intracranial hemodynamics may be at risk of further clinical events. Apart from lying flat until spontaneous recanalization or adjustment of the collateral circulation hopefully occurs, no specific treatment is currently implemented. Improving collateral flow is an attractive option in this setting. Lower body positive pressure (LBPP) is known to result in rapid venous blood shift from the lower to the upper body part, in turn improving cardiac preload and output, and is routinely used in acute hemorrhagic shock. We report here cerebral blood flow velocities measured during LBPP in this patient population. Methods This is a retrospective analysis of the clinical, physiological, and transcranial Doppler monitoring data collected during and 15 min after LBPP in 21 consecutive patients (10 females, median age: 54 years) with recently symptomatic isolated carotid occlusion/tight stenosis (unilateral in 18) mostly due to atherosclerosis or dissection. LBPP was applied for 90 min at a median 5 days after symptom onset. Results At baseline, middle-cerebral artery velocities were markedly lower on the symptomatic, as compared to asymptomatic, side. LBPP significantly improved blood flow velocities in both the symptomatic and asymptomatic middle-cerebral artery as well as the basilar artery, which persisted 15 min after discontinuing the procedure. LBPP also resulted in mild but significant increases in mean arterial blood pressure. Conclusions LBPP improved intracranial hemodynamics downstream recently symptomatic carotid occlusion/tight stenosis as well as in the contralateral and posterior circulations, which persisted after LBPP deflation. Randomized trials should determine if this easy-to-use, noninvasive, nonpharmacologic approach has long-lasting benefits on the intracranial circulation and improves functional outcome.

Preliminary Evidence of Orthostatic Intolerance and Altered Cerebral Vascular Control Following Sport-Related Concussion

Concussions have been shown to result in autonomic dysfunction and altered cerebral vascular function. We tested the hypothesis that concussed athletes (CA) would have altered cerebral vascular function during acute decreases and increases in blood pressure compared to healthy controls (HC). Ten CA (age: 20 ± 2 y, 7 females) and 10 HC (age: 21 ± 2 y, 6 females) completed 5 min of lower body negative pressure (LBNP; −40 mmHg) and 5 min of lower body positive pressure (LBPP; 20 mmHg). Protocols were randomized and separated by 10 min. Mean arterial pressure (MAP) and middle cerebral artery blood velocity (MCAv) were continuously recorded. Cerebral vascular resistance (CVR) was calculated as MAP/MCAv. Values are reported as change from baseline to the last minute achieved (LBNP) or 5 min (LBPP). There were no differences in baseline values between groups. During LBNP, there were no differences in the change for MAP (CA: −23 ± 18 vs. HC: −21 ± 17 cm/s; P = 0.80) or MCAv (CA: −13 ± 8 vs. HC: −18 ± 9 cm/s; P = 0.19). The change in CVR was different between groups (CA: −0.08 ± 0.26 vs. HC: 0.18 ± 0.24 mmHg/cm/s; P = 0.04). Total LBNP time was lower for CA (204 ± 92 s) vs. HC (297 ± 64 s; P = 0.04). During LBPP, the change in MAP was not different between groups (CA: 13 ± 6 vs. HC: 10 ± 7 mmHg; P = 0.32). The change in MCAv (CA: 7 ± 6 vs. HC: −4 ± 13 cm/s; P = 0.04) and CVR (CA: −0.06 ± 0.27 vs. HC: 0.38 ± 0.41 mmHg/cm/s; P = 0.03) were different between groups. CA exhibited impaired tolerance to LBNP and had a different cerebral vascular response to LBPP compared to HC.

Analysis of 3-D Kinematics Using H-Gait System during Walking on a Lower Body Positive Pressure Treadmill

Recently, treadmills equipped with a lower-body positive-pressure (LBPP) device have been developed to provide precise body weight support (BWS) during walking. Since lower limbs are covered in a waist-high chamber of an LBPP treadmill, a conventional motion analysis using an optical method is impossible to evaluate gait kinematics on LBPP. We have developed a wearable-sensor-based three-dimensional motion analysis system, H-Gait. The purpose of the present study was to investigate the effects of BWS by a LBPP treadmill on gait kinematics using an H-Gait system. Twenty-five healthy subjects walked at 2.5 km/h on a LBPP treadmill under the following three conditions: (1) 0%BWS, (2) 25%BWS and (3) 50%BWS conditions. Acceleration and angular velocity from seven wearable sensors were used to analyze lower limb kinematics during walking. BWS significantly decreased peak angles of hip adduction, knee adduction and ankle dorsiflexion. In particular, the peak knee adduction angle at the 50%BWS significantly decreased compared to at the 25%BWS (p = 0.012) or 0%BWS (p < 0.001). The present study showed that H-Gait system can detect the changes in gait kinematics in response to BWS by a LBPP treadmill and provided a useful clinical application of the H-Gait system to walking exercises.

Effect of Uphill Running on VO2, Heart Rate and Lactate Accumulation on Lower Body Positive Pressure Treadmills

Lower body positive pressure treadmills (LBPPTs) as a strategy to reduce musculoskeletal load are becoming more common as part of sports conditioning, although the requisite physiological parameters are unclear. To elucidate their role, ten well-trained runners (30.2 ± 3.4 years; VO2max: 60.3 ± 4.2 mL kg−1 min−1) ran at 70% of their individual velocity at VO2max (vVO2max) on a LBPPT at 80% body weight support (80% BWSet) and 90% body weight support (90% BWSet), at 0%, 2% and 7% incline. Oxygen consumption (VO2), heart rate (HR) and blood lactate accumulation (LA) were monitored. It was found that an increase in incline led to increased VO2 values of 6.8 ± 0.8 mL kg−1 min−1 (0% vs. 7%, p < 0.001) and 5.4 ± 0.8 mL kg−1 min−1 (2% vs. 7%, p < 0.001). Between 80% BWSet and 90% BWSet, there were VO2 differences of 3.3 ± 0.2 mL kg−1 min−1 (p < 0.001). HR increased with incline by 12 ± 2 bpm (0% vs. 7%, p < 0.05) and 10 ± 2 bpm (2% vs. 7%, p < 0.05). From 80% BWSet to 90% BWSet, HR increases of 6 ± 1 bpm (p < 0.001) were observed. Additionally, LA values showed differences of 0.10 ± 0.02 mmol l−1 between 80% BWSet and 90% BWSet. Those results suggest that on a LBPPT, a 2% incline (at 70% vVO2max) is not yet sufficient to produce significant physiological changes in VO2, HR and LA—as opposed to running on conventional treadmills, where significant changes are measured. However, a 7% incline increases VO2 and HR significantly. Bringing together physiological and biomechanical factors from previous studies into this practical context, it appears that a 7% incline (at 80% BWSet) may be used to keep VO2 and HR load unchanged as compared to unsupported running, while biomechanical stress is substantially reduced.