Influence of Anterior-Posterior External Surface Perturbation on Trunk Stability During Abdominal Stabilization Strategies While Sitting.

BACKGROUND Spinal and pelvic injuries during an unexpected perturbation are closely related to spinal stability, which is known to be controlled by abdominal stabilization maneuvers. This study aimed to evaluate the effects of unexpected perturbations on trunk stability and abdominal stabilization strategies in 42 sedentary adults while sitting. MATERIAL AND METHODS Abdominal stabilization strategies consisted of bracing and hollowing maneuvers. Abdominal bracing maneuvers (ABM) were focused on the abdominal wall muscles [inferior oblique (IO), exterior oblique (EO)], and abdominal hollowing maneuvers (AHM) were focused on deep muscle (TrA) activation. The subjects were instructed in abdominal stabilization maneuvers. Afterward, subjects were seated in a chair that could be moved forward or backward suddenly with the support surface. RESULTS Angular displacements of the upper thorax, lower thorax, and lumbopelvic during unexpected perturbation, with different abdominal stabilization maneuvers, were measured. During forward perturbation (d=0.71, F=10.324, P=0.001) and backward perturbation in high speed (d=0.62, F=9.265, P=0.011), there were significant differences in angular displacements of the upper thorax between hollowing and bracing maneuvers. Additionally, significant differences were found in the lumbopelvic angular displacement between the hollowing and bracing maneuvers (d=0.62, F=4.071, P=0.044). CONCLUSIONS Our findings indicate that the ABM is a better stabilizing technique for the upper thorax, and the AHM is a better stabilizing technique for the lumbopelvic region during unexpected perturbations at high speed in the seated position.

Una actualización sobre aplicaciones ortopédicas usando tecnologías de impresión tridimensional / An Update on Orthopedic Applications Using 3-Dimensional Printing Technologies / Uma atualização em aplicações ortopédicas usando tecnologias de impressão tridimensionais

Resumen En este artículo se revisan las aplicaciones tecnológicas de la impresión tridimensional (3DP) en Ortopedia. La impresión 3D es el proceso de manufacturar para construir objetos tridimensionales a través de la acumulación de material, y recientemente está llamando la atención de profesionales médicos de forma significativa. La Ortopedia es probablemente la mayor área de aplicación de esta tecnología, y está siendo probada en diversos procedimientos, desde hacer planeación quirúrgica hasta manufacturar implantes para probar su utilidad. Sin embargo, esta tecnología no ha superado completamente los problemas que surgieron en la década de los noventa, estas limitaciones serán superadas eventualmente cuando la velocidad del desarrollo tecnológico sea considerada.

Abstract This article reviews the technological applications of 3-dimensional printing (3DP) in orthopedics. 3DP is the manufacturing process to build three-dimensional object by accumulating material, and recently it is drawing the interest of medical professional significantly. Orthopedics is probably the biggest application of this technology, and is being tested from surgical planning to the implant manufacturing to prove its usefulness. The technology has not overcome the problems that arose in the 90s completely, those limitations will be overcome eventually, when the technological development speed is considered.

Resumo Este artigo descreve as aplicações tecnológicas da impressão tridimensional (3DP) em Ortopedia. Impressão 3D é o processo de manufatura para construir objectos tridimensionais, através da acumulação de material. Recentemente elas estao atraindo significativamente a atenção dos profissionais médicos. A Ortopedia é provavelmente a maior área de aplicação desta tecnologia, e está sendo testado em vários processos, desde o planejamento cirúrgico até a fabricação de implantes cirúrgicos para provar a sua utilidade. No entanto, esta tecnologia não foi consigue superar completamente os problemas que surgiram na década dos noventa. Essas limitações serao superadas quando a velocidade do desenvolvimento tecnológico seja considerado.

Feasibility of a Smartphone-Based Exercise Program for Office Workers With Neck Pain: An Individualized Approach Using a Self-Classification Algorithm.

OBJECTIVE: To explore the feasibility of a newly developed smartphone-based exercise program with an embedded self-classification algorithm for office workers with neck pain, by examining its effect on the pain intensity, functional disability, quality of life, fear avoidance, and cervical range of motion (ROM). DESIGN: Single-group, repeated-measures design. SETTING: The laboratory and participants' home and work environments. PARTICIPANTS: Offices workers with neck pain (N=23; mean age ± SD, 28.13±2.97y; 13 men). INTERVENTION: Participants were classified as having 1 of 4 types of neck pain through a self-classification algorithm implemented as a smartphone application, and conducted corresponding exercise programs for 10 to 12min/d, 3d/wk, for 8 weeks. MAIN OUTCOME MEASURES: The visual analog scale (VAS), Neck Disability Index (NDI), Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), Fear-Avoidance Beliefs Questionnaire (FABQ), and cervical ROM were measured at baseline and postintervention. RESULTS: The VAS (P<.001) and NDI score (P<.001) indicated significant improvements in pain intensity and functional disability. Quality of life showed significant improvements in the physical functioning (P=.007), bodily pain (P=.018), general health (P=.022), vitality (P=.046), and physical component scores (P=.002) of the SF-36. The FABQ, cervical ROM, and mental component score of the SF-36 showed no significant improvements. CONCLUSIONS: The smartphone-based exercise program with an embedded self-classification algorithm improves the pain intensity and perceived physical health of office workers with neck pain, although not enough to affect their mental and emotional states.

Patient perspectives on virtual reality-based rehabilitation after knee surgery: Importance of level of difficulty.

This article explored the perspectives of 25 patients regarding virtual reality (VR)-based rehabilitation following knee surgery and identified the important factors that allowed patients to immerse themselves in rehabilitation. Qualitative analysis of data collected via open-ended questionnaire and quantitative analysis of data from physical assessments and surveys were conducted. In the open-ended questionnaire, the majority of participants mentioned level of difficulty as the most common reason for selecting both the most and the least immersive exercise programs. Quantitative analysis showed that participants experienced a high level of flow (3.9 +/- 0.3 out of 5.0) and a high rate of expectation of therapeutic effect (96%) and intention of exercise adherence (96%). Further, participants with more severe pain or physical dysfunction tended to have more positive experiences (e.g., Difficulty-Skill Balance, Clear Goals, and Transformation of Time), leading to high levels of flow during VR-based rehabilitation. In conclusion, VR-based games are potentially acceptable as a motivational rehabilitation tool for patients following knee surgery. However, to best meet patients' needs, it might be useful to equip a VR program with varied levels of difficulty, taking into account the severity of the individual's knee injury. Additionally, severe pain or physical dysfunction might act as an indication rather than a contraindication for VR-based rehabilitation.

Individualized feedback-based virtual reality exercise improves older women's self-perceived health: a randomized controlled trial.

OBJECTIVES: Individualized feedback-based virtual reality (IFVR) exercise is gaining attention as a cost-effective self-management strategy, however little is known about whether older adults themselves perceive IFVR exercise effective in improving their health. Therefore, we studied the effect of IFVR exercise on health-related quality of life (HRQoL) in older women. METHODS: Fifty-four older women aged ≥65 years were randomized to either IFVR exercise group (IFVRG, n=26) or group-based exercise group (GG, n=28). Both groups received a 60-min intervention three times a week for eight weeks. The Short-Form Health Survey (SF-36) was administered. To identify the possible placebo effect, 30-Second Chair Stand Test (30SCST), 8-Foot Up-and-Go Test (8FUGT), and 2-Minute Step Test (2MST) were also administered. RESULTS: intention-to-treat analysis with adjustment for baseline levels revealed that IFVRG showed greater improvement in mental health (p=0.029) and lower body strength (p=0.042), compared to GG. Within-group analysis for HRQoL revealed that IFVRG showed an increase in role-physical (p=0.015), bodily pain (p=0.017), general health (p=0.004), vitality (p=0.010), role-emotional (p=0.007), and mental health (p<0.001), whereas GG showed an increase in role-physical (p=0.022), general health (p=0.023), and social functioning (p = 0.023). Both groups showed an increase in 30SCST, 2MST and 8FUGT (all p<0.001). CONCLUSION: IFVR exercise improved HRQoL in older women, in addition to improving physical fitness. Therefore, it might be recommended to older women as an effective self-management strategy.

A novel semi-automatic snake robot for natural orifice transluminal endoscopic surgery: preclinical tests in animal and human cadaver models (with video).

BACKGROUND AND STUDY AIMS: Natural orifice transluminal endoscopic surgery (NOTES) is an emerging surgical technique. We aimed to design, create, and evaluate a new semi-automatic snake robot for NOTES. MATERIALS AND METHODS: The snake robot employs the characteristics of both a manual endoscope and a multi-segment snake robot. This robot is inserted and retracted manually, like a classical endoscope, while its shape is controlled using embedded robot technology. The feasibility of a prototype robot for NOTES was evaluated in animals and human cadavers. RESULTS: The transverse stiffness and maneuverability of the snake robot appeared satisfactory. It could be advanced through the anus as far as the peritoneal cavity without any injury to adjacent organs. Preclinical tests showed that the device could navigate the peritoneal cavity. CONCLUSIONS: The snake robot has advantages of high transverse force and intuitive control. This new robot may be clinically superior to conventional tools for transanal NOTES.

A neuromuscular strategy to prevent spinal torsion: backward perturbation alters asymmetry of transversus abdominis muscle thickness into symmetry.

Symmetric co-contraction of the transversus abdominis (TrA) muscle is beneficial in terms of increasing trunk stability. The aim of this study was to investigate the symmetry of lateral abdominal muscle thickness during static and dynamic conditions. Fifteen male subjects (27.13 ± 5.51 years old) were instructed to sit on a chair and maintain upright posture. Every individual subject wore a jacket harness that could be backwardly attached to a 9-kg weight through a pulley system. An unexpected drop of the weight induced the transition from static to dynamic condition. The thickness of external oblique, internal oblique, and TrA muscles was measured with ultrasonography. Our results revealed more symmetry of TrA thickness during the dynamic condition (21% vs. 13%, p = 0.019) compared with the static. The symmetric muscle thickness of TrA during the dynamic condition is considered a result of more contraction on the non-dominant side. This phenomenon could be a possible strategy of deep abdominal muscles to prevent spinal torsion during sudden trunk perturbation.

Unsupervised virtual reality-based exercise program improves hip muscle strength and balance control in older adults: a pilot study.

OBJECTIVE: To assess the effects of an unsupervised virtual reality (VR)-based exercise program on hip muscle strength and balance control in older adults. DESIGN: Controlled cohort repeated-measures experimental design, a pilot study. SETTING: University research laboratory. PARTICIPANTS: Ambulatory older adults (N=32) from a local community. INTERVENTION: The VR group (n=18; mean ± SD, 68.28±3.74y; 4 men) completed the VR-based exercise program, whereas the remaining subjects in the control group (n=14; mean ± SD, 66.21±3.87y, 1 man) were asked to continue their daily routine for 8 weeks. MAIN OUTCOME MEASURES: Hip muscle strength was measured using a multimodal dynamometer, and ground reaction force using the backward stepping test and the results of the crossover stepping test were recorded using a force platform. RESULTS: The VR group showed significant improvement in hip muscle strength of the extensors, flexors, adductors, and abductors after 8 weeks (all P≤.001). However, no significant improvement was observed in the control group. The VR group had significantly greater ground reaction force on the backward stepping test (with eyes opened and closed) (all P<.005) and the crossover stepping test (with eyes opened and closed) (all P≤.001) compared with those at baseline. However, no significant improvement was observed in the control group. CONCLUSIONS: The VR-based exercise program includes the role of supervisor and feedback, which is important for older adults. Therefore, a VR-based exercise program may be a useful tool to improve decreased physical function in older adults as a home-based exercise.

Analysis of the anatomical characteristics of the pelvis in Koreans to aid in development of a NOTES platform.

Transanal endoscopic microsurgery (TEM) is a minimally invasive technique affording full-thickness resection of rectal tumors and can also be used as a platform for transrectal access to the peritoneal cavity for NOTES (natural orifice transluminal endoscopic surgery) procedures. The authors investigated the anatomical characteristics of the pelvis in Koreans to develop an ergonomically designed NOTES platform. A total of 256 patients (156 men and 100 women) who underwent pelvic magnetic resonance imaging for evaluating rectal neoplasms were enrolled for analysis. The authors retrospectively reviewed and calculated anatomical lengths and angles on pelvic magnetic resonance images and analyzed differences in pelvic anatomy in terms of patient gender, age, and body mass index. Various angulations were noted from the anal canal to the sacral promontory, attributable to the shape of the sacral bone. Minimal difference in pelvic anatomy was evident between men and women. In conclusions, the authors expect that their data will be useful in the development of ergonomic TEM-NOTES platforms.

Intensive unilateral neuromuscular training on non-dominant side of low back improves balanced muscle response and spinal stability.

Effective stabilization is important to increase sports performance. Imbalanced spinal muscle responses between the left and right sides increase the risk of spinal buckling and microtrauma at the intervertebral joints. The purpose of this study was to confirm whether intensive unilateral neuromuscular training (IUNT) focusing on the non-dominant side of the low back improves balanced muscle responses and spinal stability. The IUNT group (n = 8) performed side bridge and quadruped exercises using their non-dominant trunk muscles for 8 weeks, while the control group (n = 8) performed their regular training. Before and after the training, motion-capture cameras measured trunk angular displacement, and electromyography recorded the activities of both multifidus muscles (L4-5) during unexpected sudden forward perturbation. After the training in the IUNT group, the difference in onset time between both sides decreased to approximately 120 % compared with that before the training. The asymmetry of muscle activities also decreased from 56 to 23 %. Moreover, the angular displacement on the sagittal plane decreased to approximately 35 % after the training. We expect that IUNT focused on the non-dominant side of the low back will be useful to improve balanced back muscle responses and spinal stability during sudden trunk perturbation.

Clinical research on the ophthalmic factors affecting 3D asthenopia.

PURPOSE: Watching three-dimensional (3D) images is known to induce ocular and non-ocular symptoms, such as eye discomfort, fatigue, headache, and nausea, which can be referred to as "3D asthenopia". This study investigated ophthalmic factors associated with 3D asthenopia. METHODS: One hundred fifteen volunteers, aged 18 to 55 years, were enrolled in this study. 3D images were shown to all volunteers with 3D high-definition television for 90 minutes. Subjects who felt eyestrain were assigned to the asthenopia group (14 subjects) and subjects without symptoms were assigned to the control group (22 subjects). Ophthalmic factors including visual acuity, refractive errors, interpupillary distance, intraocular pressure, tear break-up time, near point of accommodation, presence of strabismus, stereoacuity, and retinal abnormalities were evaluated and compared between the two groups. RESULTS: Six subjects in the asthenopia group had exophoria and 1 subject in the control group had constant exotropia. None of these participants had previously noticed symptoms of strabismus. Only the presence of strabismus was significantly different between the groups (P = .008). CONCLUSION: The presence of exophoria may be a risk factor for 3D asthenopia, and 3D television may induce asthenopia by exacerbating this latent problem.

The recent progress in quantitative medical image analysis for computer aided diagnosis systems.

Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. Many different CAD schemes are being developed for use in the detection and/or characterization of various lesions found through various types of medical imaging. These imaging technologies employ conventional projection radiography, computed tomography, magnetic resonance imaging, ultrasonography, etc. In order to achieve a high performance level for a computerized diagnosis, it is important to employ effective image analysis techniques in the major steps of a CAD scheme. The main objective of this review is to attempt to introduce the diverse methods used for quantitative image analysis, and to provide a guide for clinicians.

Do ankle orthoses improve ankle proprioceptive thresholds or unipedal balance in older persons with peripheral neuropathy?

OBJECTIVE: To determine whether ankle orthoses that provide medial and lateral support, and have been found to decrease gait variability in older persons with peripheral neuropathy, decrease (improve) frontal plane ankle proprioceptive thresholds or increase unipedal stance time in that same population. DESIGN: Observational study in which unipedal stance time was determined with a stopwatch, and frontal plane ankle (inversion and eversion) proprioceptive thresholds were quantified during bipedal stance using a foot cradle system and a series of 100 rotational stimuli, in 11 older neuropathic subjects (8 men; age 72 +/- 7.1 yr) with and without ankle orthoses. RESULTS: The subjects demonstrated no change in combined frontal plane (inversion + eversion) proprioceptive thresholds or unipedal stance time with vs. without the orthoses (1.06 +/- 0.56 vs. 1.13 +/- 0.39 degrees, respectively; P = 0.955 and 6.1 +/- 6.5 vs. 6.2 +/- 5.4 secs, respectively; P = 0.922). CONCLUSION: Ankle orthoses that provide medial-lateral support do not seem to change ankle inversion/eversion proprioceptive thresholds or unipedal stance time in older persons with diabetic peripheral neuropathy. Previously identified improvements in gait variability using orthoses in this population are therefore likely related to an orthotically induced stiffening of the ankle rather than a change in ankle afferent function.

Polarization dependence suppression of optical fiber grating sensor in a π-shifted Sagnac loop interferometer.

In the sensing applications of optical fiber grating, it is necessary to reduce the transmission-type polarization dependence to isolate the sensing parameter. It is experimentally shown that the polarization-dependent spectrum of acousto-optic long-period fiber grating sensors can be suppressed in the transmission port of a π-shifted Sagnac loop interferometer. General expressions for the transmittance and reflectance are derived for transmission-type, reflection-type, and partially reflecting/transmitting-type polarization-dependent optical devices. The compensation of polarization dependence through the counter propagation in the Sagnac loop interferometer is quantitatively measured for a commercial in-line polarizer and an acousto-optic long-period fiber grating sensor.

Frontal plane ankle proprioceptive thresholds and unipedal balance.

Reliable unipedal balance is fundamental to safe ambulation. Accordingly, older persons with peripheral neuropathy (PN), who are at increased risk for falls, demonstrate impaired unipedal balance. To explore the relationship between afferent function and unipedal balance, frontal plane proprioceptive thresholds at the ankle were quantified in 22 subjects (72.5 +/- 6.3 years; 11 with PN and 11 matched controls) while they were standing using a foot cradle system and a staircase series of 100 rotational stimuli. PN subjects, as compared to controls, demonstrated shorter median unipedal balance times (3.4 +/- 2.7 vs. 14.3 +/- 8.9 s; P = 0.0017) and greater (less precise) combined ankle inversion/eversion proprioceptive thresholds (1.17 +/- 0.36 vs. 0.65 +/- 0.37 degrees ; P = 0.0055). Combined ankle inversion/eversion proprioceptive thresholds explained approximately half the variance in unipedal balance time (R2 = 0.5138; P = 0.0004). Given prior work demonstrating a similarly strong relationship between ankle torque generation and unipedal balance, neuropathy-associated impairments in ankle frontal plane afferent and efferent function appear to be equally responsible for the inability of older persons with PN to reliably balance on one foot. They therefore provide distinct targets for intervention.