Evaluation of a Chair-Mounted Passive Trunk Orthosis: A Pilot Study on Able-Bodied Subjects

Trunk stability is important for adequate arm function due to their kinematic linkage. People with Duchenne muscular dystrophy (DMD) can benefit from trunk-assistive devices for seated daily activities, but existing devices limit trunk movement to forward bending. We developed a new trunk orthosis that has spring and pulley design. This study evaluated orthosis performance with 40 able-bodied subjects under with and without orthosis condition in 20 seated tasks for trunk rotation, forward bending, and side bending movements. Subjects adopted static posture in specific trunk orientation while their muscle activity was recorded. They also rated the subjective scales of perceived exertion and usability. A percent change in muscle activity for each task, due to orthosis use, is reported. Significant muscle activity reductions up to 31% and 65% were observed in lumbar and thoracic erector spinae muscles, respectively. Using three-way ANOVA, we found these reductions to be specific to the task direction and the choice of upper limb that is used to perform the asymmetric tasks. A total of 70% participants reported acceptable usability and ~1-point increase in exertion was found for maximum voluntary reaching with the orthosis. The outcomes of this study are promising, though tested on able-bodied subjects. Hence, orthosis mounted on wheelchairs should be further evaluated on DMD patients.

Validation and Assessment of a Posture Measurement System with Magneto-Inertial Measurement Units

Inappropriate posture and the presence of spinal disorders require specific monitoring systems. In clinical settings, posture evaluation is commonly performed with visual observation, electrogoniometers or motion capture systems (MoCaps). Developing a measurement system that can be easily used also in non-structured environments would be highly beneficial for accurate posture monitoring. This work proposes a system based on three magneto-inertial measurement units (MIMU), placed on the backs of seventeen volunteers on the T3, T12 and S1 vertebrae. The reference system used for validation is a stereophotogrammetric motion capture system. The volunteers performed forward bending and sit-to-stand tests. The measured variables for identifying the posture were the kyphosis and the lordosis angles, as well as the range of movement (ROM) of the body segments. The comparison between MIMU and MoCap provided a maximum RMSE of 5.6° for the kyphosis and the lordosis angles. The average lumbo-pelvic contribution during forward bending (41.8 ± 8.6%) and the average lumbar ROM during sit-to-stand (31.8 ± 9.8° for sitting down, 29.6 ± 7.6° for standing up) obtained with the MIMU system agree with the literature. In conclusion, the MIMU system, which is wearable, inexpensive and easy to set up in non-structured environments, has been demonstrated to be effective in posture evaluation.

Comparison of Flexion Relaxation Phenomenon Between Female Yogis and Matched Non- Athlete Group

Background: Trunk flexion is a common exercise during daily activities. Flexion relaxation phenomenon (FRP) occurs during forward bending in which there is a sudden silence of erector spinae (ES) muscles. The pattern of forward bending differs in yoga practitioners. This learned pattern probably predisposes yogis to injuries.The hypothesis of this study was that FRP differs in yogis in comparison to non-yogis individuals.Methods: This observational cross-sectional study was performed on 60 women assigned into yogis and non-athlete groups. Each participant was asked to bend forward and then return to the initial position. ES activity was recorded at L3 level, 4 cm from mid line during the trial. Trunk inclination and lumbar flexion angles were calculated at FRP onset and cessation moments. Results: The FRP phenomenon occurred in 80% of yoga practitioners in comparison to 96.7% in the control group. Trunk inclination angle was significantly greater at FRP initiation in yogis compared to control group. Lumbar flexion angle was not different between the groups. Conclusions: It is concluded that the altered pattern of forward bending observed in yogis may change patterns of ES muscles activity if it becomes part of a person's daily lifestyle which might predispose these muscles to fatigue and subsequent injuries.

1365Does pain self-efficacy influence initial bending following exercise in adults with chronic low back pain?

Background Differences in pain self-efficacy between individuals with chronic low back pain (CLBP) may partly explain why response to exercise varies. The aim of this study was to determine if pain self-efficacy influences initial forward bending following an exercise intervention in adults with CLBP. Methods A total of 69 adults (18-65 years old) with moderate-severe CLBP-related disability who presented to a primary care physiotherapy clinic in Melbourne, Australia underwent baseline assessment of pain self-efficacy, pain intensity and kinesiophobia, prior to participation in one of two 12-week exercise interventions. Two outcome measures (lumbar and hip flexion range of motion (ROM) over the first quarter of forward bending from stance), were assessed at baseline, 6 and 12-weeks. Multiple linear mixed-effects modelling was performed for each outcome measure. Results For every 10-point increase in baseline pain self-efficacy, lumbar flexion ROM during initial bending decreased by an estimated mean 0.51 (95% CI: -1.41, 0.39) and 0.94 (95% CI: -1.75, -0.13) degrees at 6 and 12-weeks, respectively. Similarly, hip flexion ROM during initial bending decreased by an estimated mean 1.64 (95% CI: -3.70, 0.41) and 1.43 (95% CI: -3.34, 0.48) degrees at 6 and 12-weeks, respectively, per 10-point increase in baseline pain self-efficacy. Conclusions Pain self-efficacy did not influence initial forward bending following a 12-week exercise intervention. As the exercises were not targeted to improve bending, further research is required to verify these findings. Key message Pain self-efficacy may not explain variations in initial forward bending following an exercise intervention in adults with CLBP.

RESEARCH ON THE INFLUENCE OF SPORT DANCE ON PHYSICAL HEALTH IN NATIONAL FITNESS EXERCISE

ABSTRACT Introduction: Sports dance is widely known as a competitive game, but as a leisure activity, there is little research on the efficacy of human health and fitness. Sports dance, as a popular national fitness exercise, has sound health promotion effects. At present, domestic and foreign researches mostly focus on the impact of sports dance on young men and women. Objective: This study will explore the influence of regular physical dance exercises on the body shape, function, and quality of middle-aged and older adults, provide a scientific basis for the role of physical dance in national fitness. Methods: This study recruited 20 healthy middle-aged and elderly members of a leisure sports dance club without professional dance experience for three months of dance training. The first two weeks are pre-experiments five times a week. Each exercise time is 60 minutes. The last ten weeks are formal experiments, two times a week, 90 minutes each time, and no other physical exercises are involved in everyday life. By comparing part of the body shape, physical function, and physical fitness index before and after the experiment, the impact of sports dance on middle-aged and older adults’ healthy physical fitness is evaluated. Results: After three months of physical dance exercise with different dance styles, in male, BMI index, body fat percentage, waist circumference, hip circumference, and thigh circumference indicators all decreased, but there was no significant difference. In women, BMI index, body fat percentage (P<0.01), waist circumference (P<0.05), diastolic blood pressure (P<0.01), sitting body forward bending (P<0.05), and standing with one foot and closed eyes all increased. In women, the indexes of grip strength (P<0.01), forward bending in sitting position (P<0.055), and standing with eyes closed on one foot all increased. Conclusions: It is suggested that long-term moderate-intensity aerobic sport dance exercise can improve the body shape of middle-aged and older adults and help increase physical fitness; meanwhile, sports dance can effectively improve the cardiovascular function of middle-aged and elderly subjects. Level of evidence II; Therapeutic studies - investigation of treatment results.

Intracardiac platypnea–orthodeoxia syndrome diagnosed by forward-bending and abdominal compression

Intracardiac platypnea–orthodeoxia syndrome (POS) is a pathological condition that leads to a reduction in oxygenation in the sitting position. The detection rate of patent foramen ovale that causes POS increases with Valsalva manoeuvre and cough. We report the case of a 92-year-old woman with POS, which could not be diagnosed in the sitting position. The Valsalva manoeuvre could not be performed because of dementia, and POS was diagnosed on the forward-bending position and abdominal compression. It was assumed that forward-bending increases the right atrial pressure by compressing the right ventricle along with elongation of the aorta, and abdominal compression increases the shunt volume by increasing the venous return. If POS is suspected in patients with dementia which cannot be diagnosed in the sitting position, forward-bending and abdominal compression, instead of the Valsalva manoeuvre, might be useful.

Spinal mobility in radiographic axial spondyloarthritis: criterion concurrent validity of classic and novel measurements

Background Limitations in spinal mobility are a characteristic feature of Axial Spondyloarthritis. Current clinical measurements of spinal mobility have shown low criterion-concurrent validity. This study sought to evaluate criterion-concurrent validity for a clinically feasible measurement method of measuring spine mobility using tri-axial accelerometers. Methods Fifteen radiographic-Spondyloarthritis patients were recruited for this study. Two postural reference radiographs, followed by three trials in forward, left and right lateral bending were taken. For all trials, three measurements were collected: tape (Original Schober’s, Modified Schober’s, Modified-Modified Schober’s, Lateral Spinal Flexion Test and Domjan Test), followed immediately by synchronized radiograph and accelerometer measurements at end range of forward and bilateral lateral flexion. The criterion-concurrent validity of all measurement methods was compared to the radiographic measures using Pearson’s correlation coefficients. A Bland-Altman analysis was conducted to assess agreement. Results In forward bending, the accelerometer method (r = 0.590, p = 0.010) had a stronger correlation to the radiographic measures than all tape measures. In lateral bending, the Lateral Spinal Flexion tape measure (r = 0.743, p = 0.001) correlated stronger than the accelerometer method (r = 0.556, p = 0.016). The Domjan test of bilateral bending (r = 0.708, p = 0.002) had a stronger correlation to the radiographic measure than the accelerometer method. Conclusions Accelerometer measures demonstrated superior criterion-concurrent validity compared to current tape measures of spinal mobility in forward bending. While a moderate correlation exists between accelerometer and radiographs in lateral bending, the Lateral Spinal Flexion Test and Domjan Test were found to have the best criterion-concurrent validity of all tests examined in this study.