Accuracy of Video-Based Gait Analysis Using Pose Estimation During Treadmill Walking Versus Overground Walking in Persons After Stroke.

OBJECTIVE: Video-based pose estimation is an emerging technology that shows significant promise for improving clinical gait analysis by enabling quantitative movement analysis with little costs of money, time, or effort. The objective of this study is to determine the accuracy of pose estimation-based gait analysis when video recordings are constrained to 3 common clinical or in-home settings (ie, frontal and sagittal views of overground walking and sagittal views of treadmill walking). METHODS: Simultaneous video and motion capture recordings were collected from 30 persons after stroke during overground and treadmill walking. Spatiotemporal and kinematic gait parameters were calculated from videos using an open-source human pose estimation algorithm and from motion capture data using traditional gait analysis. Repeated-measures analyses of variance were then used to assess the accuracy of the pose estimation-based gait analysis across the different settings, and the authors examined Pearson and intraclass correlations with ground-truth motion capture data. RESULTS: Sagittal videos of overground and treadmill walking led to more accurate measurements of spatiotemporal gait parameters versus frontal videos of overground walking. Sagittal videos of overground walking resulted in the strongest correlations between video-based and motion capture measurements of lower extremity joint kinematics. Video-based measurements of hip and knee kinematics showed stronger correlations with motion capture versus ankle kinematics for both overground and treadmill walking. CONCLUSION: Video-based gait analysis using pose estimation provides accurate measurements of step length, step time, and hip and knee kinematics during overground and treadmill walking in persons after stroke. Generally, sagittal videos of overground gait provide the most accurate results. IMPACT: Many clinicians lack access to expensive gait analysis tools that can help identify patient-specific gait deviations and guide therapy decisions. These findings show that video-based methods that require only common household devices provide accurate measurements of a variety of gait parameters in persons after stroke and could make quantitative gait analysis significantly more accessible.

Complex Regional Pain Syndrome: Evidence-Based Advances in Concepts and Treatments.

PURPOSE OF REVIEW: This review presents the most current information about the epidemiology of complex regional pain syndrome (CRPS), classification and diagnostic criteria, childhood CRPS, subtypes, pathophysiology, conventional and less conventional treatments, and preventive strategies. RECENT FINDINGS: CRPS is a painful disorder with multifactorial pathophysiology. The data describe sensitization of the central and peripheral nervous systems, inflammation, possible genetic factors, sympatho-afferent coupling, autoimmunity, and mental health factors as contributors to the syndrome. In addition to conventional subtypes (type I and type II), cluster analyses have uncovered other proposed subtypes. Prevalence of CRPS is approximately 1.2%, female gender is consistently associated with a higher risk of development, and substantial physical, emotional, and financial costs can result from the syndrome. Children with CRPS seem to benefit from multifaceted physical therapy leading to a high percentage of symptom-free patients. The best available evidence along with standard clinical practice supports pharmacological agents, physical and occupational therapy, sympathetic blocks for engaging physical restoration, steroids for acute CRPS, neuromodulation, ketamine, and intrathecal baclofen as therapeutic approaches. There are many emerging treatments that can be considered as a part of individualized, patient-centered care. Vitamin C may be preventive. CRPS can lead to progressively painful sensory and vascular changes, edema, limb weakness, and trophic disturbances, all of which substantially erode healthy living. Despite some progress in research, more comprehensive basic science investigation is needed to clarify the molecular mechanisms of the disease so that targeted treatments can be developed for better outcomes. Incorporating a variety of standard therapies with different modes of action may offer the most effective analgesia. Introducing less conventional approaches may also be helpful when traditional treatments fail to provide sufficient improvement.

Kinematics of shoulder, trunk, pelvis, and hip while reaching forward to progressively distant targets.

INTRODUCTION: Information on the normal contribution of various body regions to forward reaching provides a basis for assessing the maneuver. The purpose of this study was to describe the kinematics of the shoulder, trunk, pelvis, and hip of healthy young males while they stood and reached toward a target at arm's length and 5%, 10%, 15%, and 20% of body height beyond. METHOD: Twelve healthy adult males were marked with 22 spherical reflective markers. Two trials of unilateral forward reaching were performed towards a target placed at five target distances. Motion was captured via reflective markers and an infrared camera system. RESULTS: Sagittal and transverse plane motions demonstrated high reliability between trials at each target distance (ICC = 0.716 trunk flexion to 0.977 shoulder flexion). Shoulder flexion and horizontal abduction were major contributors to forward reaching with components of trunk flexion and left trunk rotation at all target distances. Hip flexion, pelvic tilt, left pelvis rotation, and hip external rotation made notable contributions at the furthest targets. All motions became more pronounced as target distance increased (P ≤ .001). CONCLUSION: Kinematic analysis demonstrated that right forward reaching requires composite movements at the shoulder, trunk, pelvis, and hip. The contribution of each body region to forward reaching became more pronounced as the target became more distant. These findings may be helpful when identifying localized movement impairments contributing to limited forward reach in a clinical population, although clinical validation is needed.

Validity and Reliability of Jump Height Measurements Obtained From Nonathletic Populations With the VERT Device.

BACKGROUND AND PURPOSE: Vertical jump (VJ) is commonly used to assess lower extremity power in athletic populations. A portable device called the VERT has been validated for this population, but not in nonathletic populations. We sought in this study to assess the clinimetric properties of VJ height measurements obtained with the VERT from older and younger nonathletes. METHODS: Twenty-eight participants (14 older, 14 younger, evenly split between male and female) completed 2 submaximal and 3 maximal VJ trials wearing the VERT during 2 sessions separated by 5 to 9 days. During the first session, their VJ heights were also monitored using motion capture video. RESULTS: Analysis revealed concurrent validity of the VERT against motion capture (intraclass correlation coefficient [ICC3,1] = 0.826-0.950) and known-groups validity of the VERT based on age and gender (P < .001). Strong parallel reliability against a second VERT device (ICC = 0.992) was demonstrated as was strong test-retest reliability (ICC = 0.968). CONCLUSIONS: The VERT device provides valid and reliable measures of VJ height in nonathletic populations, including older adults. However, the VERT may not be suitable for recording the low jump heights of some older adults.

Evaluation of Earbud and Wristwatch Heart Rate Monitors during Aerobic and Resistance Training.

Assessment of biometrics during exercise is evolving to create devices that are "all-inclusive", in an effort to decrease the number of devices required during exercise while providing comprehensive and accurate biometric measures. The purpose of this study was to determine the accuracy of two optical heart rate monitors, the Jabra earbud and the Mio Alpha wristwatch, during aerobic and anaerobic exercise. Twenty-two recreationally active participants (25.4 ± 6.9 years, 171 ± 11 cm, 73.9 ± 3.1 kg, and 25.2 ± 9.2% body fat) completed this study. Participants completed 30 minutes of treadmill activity, 25 minutes of high-intensity interval exercise (HIT), and 40 minutes of continuous outdoor activity of their choice, walking or running. Three heart rate (HR) monitors, (Polar chest strap, Mio Alpha, Jabra earbud) were worn during all exercises, with the Polar chest strap serving as the benchmark. HR was assessed in one-second intervals. Analyses included mean bias, mean absolute percent error (MAPE), and Lin's concordance coefficient. Overall, the Mio Alpha had a MAPE of 5.73 ± 10.19% and a moderate correlation with the benchmark, r(c) = 0.771, performing better in the treadmill and outdoor conditions. The Jabra earbud had a MAPE of 3.14 ± 6.13%, and a high correlation with the benchmark, r(c) = 0.939, performing well in all three conditions. Placing a HR monitor in an earbud is a viable option for obtaining an accurate HR assessment during different types of exercise. The accuracy of the Mio Alpha was likely affected by wrist movements during the HIT training.

Acute Effects of Posture Shirts on Rounded-Shoulder and Forward-Head Posture in College Students.

CONTEXT: Rounded-shoulder and forward-head posture can be contributing factors to shoulder pain. Corrective techniques such as manual therapy and exercise have been shown to improve these altered postures, but there is little evidence that corrective garments such as posture shirts can alter posture. OBJECTIVES: To determine the acute effects of corrective postureshirt use on rounded-shoulder and forward-head posture in asymptomatic college students. DESIGN: Repeated-measures intervention study with counterbalanced conditions. SETTING: Research laboratory. PARTICIPANTS: 24 members of the general student body of a university, 18-25 y old, with a forward shoulder angle (FSA) >52° and no history of upper-extremity surgery, scoliosis, active shoulder pain, or shoulder pain in the previous 3 mo that restricted participation for 3 consecutive days. INTERVENTIONS: Photographic posture assessment under a control condition, under a sham or treatment condition (counterbalanced), under another control condition, and treatment or sham. MAIN OUTCOME MEASURES: FSA and forward head angle (FHA) calculated from a lateral photograph. RESULTS: FSA decreased relative to the control condition while participants wore the sham shirt (P = .029) but not the corrective posture shirt (P = 1.00). FHA was unchanged between groups (P = .371). CONCLUSIONS: Application of a corrective posture shirt did not acutely alter FSA or FHA, while application of a sham shirt may decrease FSA at rest.