Delayed hollow viscus injury with an occult seatbelt abrasion presenting as a small bowel obstruction.

We present the case of a previously healthy 29-year-old male who presented with a small bowel obstruction in the absence of previous abdominal surgery who was found to have evidence of an occult seatbeltabrasion and ultimately multifocal hollow viscus injury secondary to blunt abdominal trauma at the time of exploratory laparotomy. Hollow viscus injury is a rare, but potentially life-threatening, complication of blunt abdominal trauma. While cross-sectional imaging is an important diagnostic tool, results must be considered within a patient's clinical context as delays in surgical management can lead to significant morbidity and mortality.

Overground gait adaptability in older adults with type 2 diabetes in response to virtual targets and physical obstacles.

BACKGROUND: To step over an unexpected obstacle, individuals adapt gait; they adjust step length in the anterior-posterior direction prior to the obstacle and minimum toe clearance height in the vertical direction during obstacle avoidance. Inability to adapt gait may lead to falls in older adults with diabetes as the results of the effects of diabetes on the sensory-motor control system. Therefore, this study aimed to investigate gait adaptability in older adults with diabetes. RESEARCH QUESTION: Would diabetes impair gait adaptability and increase sagittal foot adjustment errors? METHODS: Three cohorts of 16 people were recruited: young adults (Group I), healthy older adults (Group II), and older adults with diabetes (Group III). Participants walked in baseline at their comfortable speeds. They then walked and responded to what was presented in gait adaptability tests, which included 40 trials with four random conditions: step shortening, step lengthening, obstacle avoiding, and walking through. Virtual step length targets were 40% of the baseline step length longer or shorter than the mean baseline step length; the actual obstacle was a 5-cm height across the walkway. A Vicon three-dimensional motion capture system and four A.M.T.I force plates were used to quantify spatiotemporal parameters of a gait cycle and sagittal foot adjustment errors (differences between desired and actual responses). Analyses of variance (ANOVA) repeated measured tests were used to investigate group and condition effects on dependent gait parameters at a significance level of 0.05. RESULTS: Statistical analyses of Group I (n = 16), Group II (n = 14) and Group III (n = 13) revealed that gait parameters did not differ between groups in baseline. However, they were significantly different in adaptability tests. Group III significantly increased their stance and double support times in adaptability tests, but these adaptations did not reduce their sagittal foot adjustment errors. They had the greatest step length errors and lowest toe-obstacle clearance, which could cause them to touch the obstacle more. SIGNIFICANCE: The presented gait adaptability tests may serve as entry tests for falls prevention programs.

Effects of diabetes mellitus on step length and minimum toe clearance adaptation.

BACKGROUND: Adaptive gait involves the ability to adjust the leading foot in response to the requirement of dynamic environments during walking. Accurate adjustments of the minimum toe clearance (MTC) height and step length can prevent older people from falling when walking and responding to hazards. Although older people with diabetes fall more frequently than healthy older adults, no previous studies have quantified their adaptive gait abilities. This study aimed to investigate the effects of diabetes mellitus on step length and MTC height adjustments using a non-immersive virtual-reality system. METHODS: Sixteen young adults (26 ± 5 years, 7 females), 16 healthy older adults (68 ± 5 years, 6 females), and 16 older adults with diabetes (70 ± 5 years, 6 females) completed adaptability tests while walking on a treadmill. A computer system visualised a continuous real-time signal of absolute step length and MTC on a monitor. Each person responded to four discrete participant-specific step length and MTC visual targets that were presented on the same signal. Tasks were to match the peaks of interest on each signal to presented targets. Targets were 10% longer or shorter than the mean baseline step length, and 2.5 cm, and 3.5 cm higher than the mean baseline MTC. When a target was displayed, it remained unchanged for 10 consecutive foot displacement adaptation attempts. Then, the target was removed and a new target or the same target was present after 10 consecutive steps and remained for 10 steps. Each target was randomly presented three times (3 × 10). Step length and MTC height adjustments in response to targets were measured and compared among groups. RESULTS: Mean preferred walking speeds were not different among groups significantly when no targets were presented on the monitor in baseline walking. However, when participants walked on a treadmill while attempting to match step lengths or MTC heights to displayed targets on the monitor, the group with diabetes had reduced step length and MTC adjustments compared with other groups significantly. They showed greater errors (differences between their step lengths/MTC heights and presented targets) on the monitor. CONCLUSIONS: This study quantified reduced abilities for older individuals with diabetes to adjust both step length and MTC in response to stimuli compared to healthy older counterparts. Reduced step length and MTC height adjustments can increase falls in at risk populations. The presented virtual-reality system has merits for assessing and training step and MTC adaptation.

Overground gait training using virtual reality aimed at gait symmetry.

This study investigated if training in a virtual reality (VR) environment that provides visual and audio biofeedback on foot placement can induce changes to spatial and temporal parameters of gait during overground walking. Eighteen healthy young adults walked for 23 min back and forth on an instrumented walkway in three different conditions: (i) real environment (RE), (ii) virtual environment (VE) with no biofeedback, and (iii) VE with biofeedback. Visual and audio biofeedback while stepping on virtual footprint targets appearing along a straight path encouraged participants to walk with an asymmetrical step length (SL). A repeated-measures, one-way ANOVA, followed by a pairwise comparison post-hoc analysis with Bonferroni's correction, was performed to compare the step length difference (SLD), stance phase percentage difference (SPPD), and double-support percentage difference (DSPD) between early and late phases of all walking conditions. The results demonstrate the efficacy of the VE biofeedback system for training asymmetrical gait patterns. Participants temporarily adapted an asymmetrical gait pattern immediately post-training in the VE. Induced asymmetries persisted significantly while later walking in the RE. Asymmetry was significant in the spatial parameters of gait (SLD) but not in the temporal parameters (SPPD and DSPD). This paper demonstrates a method to induce unilateral changes in spatial parameters of gait using a novel VR tool. This study provides a proof-of-concept validation that VR biofeedback training can be conducted directly overground and could potentially provide a new method for treatment of hemiplegic gait or asymmetrical walking.

Toward a hybrid exoskeleton for crouch gait in children with cerebral palsy: neuromuscular electrical stimulation for improved knee extension.

BACKGROUND: Neuromuscular Electrical Stimulation (NMES) has been utilized for many years in cerebral palsy (CP) with limited success despite its inherent potential for improving muscle size and/or strength, inhibiting or reducing spasticity, and enhancing motor performance during functional activities such as gait. While surface NMES has been shown to successfully improve foot drop in CP and stroke, correction of more complex gait abnormalities in CP such as flexed knee (crouch) gait remains challenging due to the level of stimulation needed for the quadriceps muscles that must be balanced with patient tolerability and the ability to deliver NMES assistance at precise times within a gait cycle. METHODS: This paper outlines the design and evaluation of a custom, noninvasive NMES system that can trigger and adjust electrical stimulation in real-time. Further, this study demonstrates feasibility of one possible application for this digitally-controlled NMES system as a component of a pediatric robotic exoskeleton to provide on-demand stimulation to leg muscles within specific phases of the gait cycle for those with CP and other neurological disorders who still have lower limb sensation and volitional control. A graphical user interface was developed to digitally set stimulation parameters (amplitude, pulse width, and frequency), timing, and intensity during walking. Benchtop testing characterized system delay and power output. System performance was investigated during a single session that consisted of four overground walking conditions in a 15-year-old male with bilateral spastic CP, GMFCS Level III: (1) his current Ankle-Foot Orthosis (AFO); (2) unassisted Exoskeleton; (3) NMES of the vastus lateralis; and (4) NMES of the vastus lateralis and rectus femoris. We hypothesized in this participant with crouch gait that NMES triggered with low latency to knee extensor muscles during stance would have a modest but positive effect on knee extension during stance. RESULTS: The system delivers four channels of NMES with average delays of 16.5 ± 13.5 ms. Walking results show NMES to the vastus lateralis and rectus femoris during stance immediately improved mean peak knee extension during mid-stance (p = 0.003*) and total knee excursion (p = 0.009*) in the more affected leg. The electrical design, microcontroller software and graphical user interface developed here are included as open source material to facilitate additional research into digitally-controlled surface stimulation ( github.com/NIHFAB/NMES ). CONCLUSIONS: The custom, digitally-controlled NMES system can reliably trigger electrical stimulation with low latency. Precisely timed delivery of electrical stimulation to the quadriceps is a promising treatment for crouch. Our ultimate goal is to synchronize NMES with robotic knee extension assistance to create a hybrid NMES-exoskeleton device for gait rehabilitation in children with flexed knee gait from CP as well as from other pediatric disorders. TRIAL REGISTRATION: clinicaltrials.gov, ID: NCT01961557 . Registered 11 October 2013; Last Updated 27 January 2020.

Age effects on step adaptation during treadmill walking with continuous step length biofeedback.

BACKGROUND: The inability to adjust step length can lead to falls in older people when navigating everyday terrain. Precisely targeted forward placement of the leading foot, constituting step length adjustment, is required for adaptive gait control, but this ability may reduce with ageing. The objective of this study was to investigate ageing effects on step length adaptation using real-time biofeedback. RESEARCH QUESTION: Does ageing affect the ability to adapt step length to match a target using real-time biofeedback? METHODS: Fifteen older adults (67 ± 3 years; 8 females) and 27 young adults (24 ± 4 years; 13 females) completed a step length adaptation test while walking at preferred speed on a treadmill. The test involved walking while viewing a monitor at the front of the treadmill that showed a real-time signal of absolute left-right foot displacement. The task was to match the local maxima of the signal (i.e. step length) to two target conditions, at 10 % longer or 10 % shorter than mean baseline step length. When the target was displayed, it remained unchanged for a set of 10 consecutive step attempts. Three sets of 10 attempts for each target condition were allocated in random order, for a total of 30 step attempts per target. Average absolute error and average error (bias) of step length accuracy was computed for each target condition and compared between groups. RESULTS: The step adaptation test identified that older adults had greater mean absolute error for both short and long step targets and showed a step length-dependent bias significantly different to the young. SIGNIFICANCE: Real-time foot position feedback could be a useful tool to train and evaluate step adaptation in older people.