Spinal posture during stooped walking under vertical space constraints

Impacts of gait biomechanics of patients with thoracolumbar kyphosis secondary to Scheuermann's disease

Introduction: Thoracolumbar kyphosis (TLK) is a common feature in patients with spinal deformities. However, due to limited studies, the impacts of TLK on gait have not been reported. The objective of the study was to quantify and evaluate the impacts of gait biomechanics of patients with TLK secondary to Scheuermann's disease. Methods: Twenty cases of Scheuermann's disease patients with TLK and twenty cases of asymptomatic participants were recruited into this study. And the gait motion analysis was conducted. Results: The stride length was shorter in the TLK group compared to control group (1.24 ± 0.11 m vs. 1.36 ± 0.21 m, p = 0.04). Compared to control group, the stride time and step time were more prolonged in the TLK group (1.18 ± 0.11s vs. 1.11 ± 0.08 s, p = 0.03; 0.59 ± 0.06 s vs. 0.56 ± 0.04 s, p = 0.04). The gait speed of the TLK group was significantly slower than it of control group (1.05 ± 0.12 m/s vs. 1.17 ± 0.14 m/s, p = 0.01); In the sagittal plane, the range of motion (ROM) of the hip in the TLK group was significantly smaller than that of the control group (37.71 ± 4.35° vs. 40.05 ± 3.71°, p = 0.00). In the transverse plane, the adduction/abduction ROMs of the knee and ankle, as well as the internal and external rotation of the knee, were smaller in TLK group than ROMs in the control group (4.66 ± 2.21° vs. 5.61 ± 1.82°, p = 0.00; 11.48 ± 3.97° vs. 13.16 ± 5.6°, p = 0.02; 9.00 ± 5.14° vs. 12.95 ± 5.78°, p = 0.00). Discussion: The main finding of this study was that measurements of gait patterns and joint movement of the TLK group were significantly lower than those of the control group. And these impacts have the potential to exacerbate degenerative progress of joints in the lower extremities. These abnormal features of gait can also serve as a guideline for physicians to focus on TLK in these patients.

The effects of lumbo-pelvic postural taping on gait parameters in patients with lumbar spinal stenosis

BACKGROUND

Altered gait patterns with lumbar-flexed posture threaten the quality of life in patients with lumbar spinal stenosis; however, few studies have developed management strategies to improve gait patterns and lumbo-pelvic posture. The present study investigated the effects of lumbo-pelvic postural taping on pelvic tilt, spatiotemporal gait parameters, and pain during walking in patients with lumbar spinal stenosis.

METHODS

The pelvic tilt and gait parameters were assessed in 20 patients with lumbar spinal stenosis before sustained walking using a palpation meter and GAITRite system, respectively. Next, the participants were asked to walk on the ground for 20 min or until they complained of symptoms of neurogenic claudication. Pelvic tilt and gait parameters were measured immediately after the manifestation of neurogenic claudication followed by the application of lumbo-pelvic postural taping. The participants rated the pain intensity using a visual analog scale. Changes in dependent variables among the conditions were analyzed using a one-way repeated-measures analysis of variance.

FINDINGS

The results show a decreased pelvic anterior tilt, walking velocity, and step and stride lengths, as well as an increased base of support and pain after severe symptoms of neurogenic claudication (P<0.05). However, a greater pelvic anterior tilt, faster walking velocity with a longer step and stride length, and decreased base of support and pain were found after the application of postural taping (P≤0.001).

INTERPRETATION

These findings suggest that lumbo-pelvic postural taping can provide beneficial management for improving gait patterns and lumbo-pelvic posture in patients with lumbar spinal stenosis.

MEASURING LUMBAR SAGITTAL POSTURE IN SEWAGE WORKERS USING AN ULTRASONIC DEVICE

Because the degree and duration of lumbar flexion during sewage work have only been assessed on the basis of subjective reports, the purpose of this study was to investigate the usability of a measurement system for the non-invasive assessment of lumbar sagittal posture during sewage work using ultrasound. The validity of an ultrasonic measurement device was investigated in 16 healthy individuals by comparing the measurements obtained with the device with both Schober and electronic inclinometer measurements. To determine the intra-rater reliability of the ultrasonic device, short-term, medium-term, and long-term test-retest data were collected. Moreover, the percentage of the work time sewage workers spend in each of seven lumbar flexion categories within their individual lumbar flexion range of motion was assessed. Pearson's correlation coefficients of ≥ 0.88 indicate high validity between the methods. The intraclass correlation coefficients between tests and retests (≥ 0.88) demonstrate high reproducibility of the measurement procedures. Sewage workers spend about 25% of their work day in the most extreme of the seven lumbar posture categories. Also, testing did not interfere with the workers' normal work routine. The validity and reliability data as well as the trouble-free technical performance of the ultrasonic device support its usability for the continuous measurement of lumbar posture during sewage work.

Factors associated with the subject's ability to quantify their lumbar flexion demands at work

Continuous measurements of lumbar posture provide the basis for determining the factors influencing the difference between subjective and objective assessments of lumbar posture. The lumbar flexion posture during an entire work day was registered in a group of 13 sewage workers and 14 physical therapists. Subjective lumbar posture data, perceived occupational stress, job satisfaction and 12 month prevalence of low back pain were obtained using standardized questionnaires. For the entire sample, a significant positive correlation was found between the degree of overestimation of the lumbar bending demands at work and the level of occupational stress (p > 0.01) as well as the low back pain prevalence in the past 12 months. Continuous measurement of spinal posture is an important tool not only for comparisons of posture demands during various activities but also for investigations into the complex interactions between the biomechanical and psychosocial determinants of low back pain.

Posture of the trunk in the sagittal plane is associated with gait in community-dwelling elderly population

OBJECTIVES

The purpose of this study was to evaluate whether abnormal posture of the trunk in the sagittal plane would affect gait and functional performance in the elderly.

BACKGROUND

There have been very few reports on whether posture of the trunk is related to gait and functional performance.

METHODS

The study group included 237 participants with a mean age of 80.0 years (range 65-94 years). The posture of the trunk in a standing position of the sagittal plane was classified into five groups. We investigated the relationship between the trunk posture in the sagittal plane and age with gait parameters and functional performance such as timed up & go test and functional reach.

RESULTS

In the elderly subjects of normal posture, there was no difference between those in the 65-79 years age group and those in the 80 years and older age group in terms of any gait parameters. Walking abilities were significantly decreased in the abnormal posture groups. Among the abnormal posture groups, elderly in the lumbar kyphosis group had walking disabilities that did not differ between age groups, whereas gait disturbance in the thoracic kyphosis group showed a positive relation with age.

CONCLUSIONS

Posture of the trunk in the sagittal plane was associated not only with the distance and time parameter of gait, but also with functional performance in the elderly.

Model-guided derivation of lumbar vertebral kinematics in vivo reveals the difference between external marker-defined and internal segmental rotations

This study investigated whether the external marker-defined spine inter-segmental rotation is different from the internal vertebral rotation, and explored how to estimate the latter from limited surface measurement. A kinematic model was first created to elucidate analytically the relation between the external and internal rotations. A novel approach guided by the model was proposed for deriving vertebral centers of rotation (CORs) from measured planar trajectories of skin-surface markers. The approach involved a recursive procedure for establishing local (anatomical) coordinate systems, and an optimization routine that identified the maximum-likelihood circles best fitting the marker trajectories in local coordinate systems. An experiment with 10 subjects (5 males and 5 females) was conducted to test the approach along with the model. Skin-surface markers were strategically placed over individual spinous processes and other body landmarks, and recorded by an opto-electronic system while sagittally symmetric load-lifting movements were being performed. For the majority (89%) of measured motions, the COR locations for lumbar vertebrae (L2-L5) were derived successfully: solutions resulting from the optimization routine met a convergence criterion governed by the model, and were in agreement with existing data from radiographic or cadaveric studies. Empirical results confirmed the differences between the external marker-defined inter-segmental motions and corresponding internal vertebral rotations (1.1-5.8 degrees on average, all statistically significant). The study demonstrated the necessity and viability of quantifying internal vertebral kinematics when utilizing non-invasive marker-based measurement for spine-related clinical diagnosis and biomechanical modeling.

Effects of load and speed on lumbar vertebral kinematics during lifting motions

This experimental study investigated the effects of load magnitude and movement speed on lumbar vertebral kinematics during lifting task performance. Ten participants performed sagittally symmetric lifting movements with systematically varied load using either a normal or a faster-than-normal speed. Skin-surface markers were strategically placed over the participants' spinous processes and other landmarks representing major body joints and were recorded during the movements by a motion capture system. The center of rotation (COR) locations and segmental movement profiles for lumbar vertebrae L2 to L5 were derived and analyzed. Results suggested that (a) the COR locations and vertebral angular displacement were not significantly affected by the speed or load variation; (b) a faster speed tended to shorten the time to complete the acceleration for all the lumbar vertebrae considered; and (c) the load increase incurred a tendency for the L5 to complete the primary displacement in a briefer time while enduring greater peak acceleration and velocity. The findings lead to a better understanding of the relation between lifting dynamics and spinal motion. Potential applications of this research include the development of more accurate biomechanical models and software tools for depicting spinal motions and quantifying low-back stress.

Spine ergonomics

Occupational low back pain (LBP) is an immense burden for both industry and medicine. Ergonomic and personal risk factors result in LBP, but psychosocial factors can influence LBP disability. Epidemiologic studies clearly indicate the role of mechanical loads on the etiology of occupational LBP. Occupational exposures such as lifting, particularly in awkward postures; heavy lifting; or repetitive lifting are related to LBP. Fixed postures and prolonged seating are also risk factors. LBP is found in both sedentary occupations and in drivers as well as those involved in manual materials handling. Any prolonged posture will lead to static loading of the soft tissues and cause discomfort. Standing and sitting have specific advantages and disadvantages for mobility, exertion of force, energy consumption, circulatory demands, coordination, and motion control. The seated posture leads to inactivity causing an accumulation of metabolites, accelerating disk degeneration and leading to disk herniation. Driver's postures can also lead to musculoskeletal problems. Workers in a driving environment are often subjected to postural stress leading to back, neck, and upper extremity pain. This exacerbates the problems due to the vibration. Prevention is by far the treatment of choice. Improved muscle function can be preventative. Poor coordination and motor control systems are as important as endurance and strength. Fixed postures should be avoided. Seats offering good lumbar support should be used in the office. A suspension seat should be used in vehicles whenever possible. Heavy and awkward lifting should be avoided and lifting aids should be made available. Workers should report LBP as early as possible and seek medical advice if they think occupational exposure is harming them. The combined effects of the medical community, labor, and management are required to cause some impact on this problem.