Trunk Angular Kinematics Research Articles

Trunk postural control in unstable sitting: Effect of sex and low back pain status

BackgroundAdequate neuromuscular control of the lumbar spine is required to prevent lumbar injuries. A trunk postural control test protocol, controlling for the influence of body size on performance, was implemented to carry out between-subject comparisons. The aim of this study was to assess the effect of sex and low back pain status with the use of two measures of trunk postural control, the first based on chair motion, and the second based on trunk motion. MethodsThirty-six subjects (with and without low back pain) performed three 60-s trunk postural control trials with their eyes closed while seated on an instrumented wobble chair, following a calibration procedure. Chair and trunk angular kinematics were measured with an optoelectronic system. A chair-based stabilogram and a trunk-based (lumbar spine) stabilogram were created using the angular motions produced in the sagittal and frontal planes. Twenty body-sway measures were computed for each stabilogram. FindingsThe calibration task efficiently controlled for the influence of body size. Several sex effects were detected, with most of them originating from the trunk-based measures. Subjects with low back pain and healthy controls showed comparable trunk postural control. InterpretationSex differences were substantiated for the first time, but almost only with the trunk-based stabilogram, showing that the kinematic information captured on the trunk segments is quite different from what is captured on the wobble chair. Contrary to previous studies, pain status was not related to lowered trunk postural control, which can be attributed to the patients recruited or measurement reliability issues.

Trunk angular kinematics during slip-induced backward falls and activities of daily living.

Prior to developing any specific fall detection algorithm, it is critical to distinguish the unique motion features associated with fall accidents. The current study aimed to investigate the upper trunk angular kinematics during slip-induced backward falls and activities of daily living (ADLs). Ten healthy older adults (age = 75 ± 6 yr (mean ± SD)) were involved in a laboratory study. Sagittal trunk angular kinematics were measured using optical motion analysis system during normal walking, slip-induced backward falls, lying down, bending over, and various types of sitting down (SN). Trunk angular phase-plane plots were generated to reveal the motion features of falls. It was found that backward falls were characterized by a simultaneous occurrence of a slight trunk extension and an extremely high trunk extension velocity (peak average = 139.7 deg/s), as compared to ADLs (peak average = 84.1 deg/s). It was concluded that the trunk extension angular kinematics of falls were clearly distinguishable from those of ADLs from the perspective of angular phase-plane plot. Such motion features can be utilized in future studies to develop a new prior-to-impact fall detection algorithm.

Development and Evaluation of a Prior-to-Impact Fall Event Detection Algorithm

Automatic fall event detection has attracted research attention recently for its potential application in fall alarming system and wearable fall injury prevention system. Nevertheless, existing fall detection research is facing various limitations. The current study aimed to develop and validate a new fall detection algorithm using 2-D information (i.e., trunk angular velocity and trunk angle). Ten healthy elderly were involved in a laboratory study. Sagittal trunk angular kinematics was measured using inertial measurement unit during slip-induced backward falls and a variety of daily activities. The new algorithm was, on average, able to detect backward falls prior to impact, with 100% sensitivity, 95.65% specificity, and 255ms response time. Therefore, it was concluded that the new fall detection algorithm was able to effectively detect falls during motion for the elderly population.

Automatic individual calibration in fall detection – an integrative ambulatory measurement framework

The objective of the current study was to demonstrate the utility of a new integrative ambulatory measurement (IAM) framework by developing and evaluating an individual calibration function in fall detection application. Ten healthy elderly persons were involved in a laboratory study and tested in a protocol comprising various types of activities of daily living and slip-induced backward falls. Inertial measurement units attached to the trunk and thigh segments were used to measure trunk angular kinematics and thigh accelerations. The effect of individual calibration was evaluated with previously developed fall detection algorithm. The results indicated that with individual calibration, the fall detection performance achieved approximately the same level of sensitivity (100% vs. 100%) and specificity (95.25% vs. 95.65%); however, response time was significantly lower than without (249 ms vs. 255 ms). It was concluded that the automatic individual calibration using the IAM framework improves the performance of fall detection, which has a greater implication in preventing/minimising injuries associated with fall accidents.

Trunk Angular Kinematics during Slip-Induced Falls and Activities of Daily Living – Towards Developing a Fall Detector

Trunk Angular Kinematics during Slip-Induced Falls and Activities of Daily Living – Towards Developing a Fall Detector

Trunk Angular Kinematics during Slip-Induced Falls and Activities of Daily Living - Towards Developing a Fall Detector

The purpose of the current study was to investigate the trunk angular kinematics (i.e., angle and angular velocity) during slip-induced falls and activities of daily living (ADLs), with the aim to facilitate the development of a new fall detector. Ten elderly participated in a laboratory experiment, composed of normal walking, slip-induced falls, and 5 types of ADLs. Sagittal trunk kinematics was measured from optical motion analysis system. Angular phase plots were utilized to characterize falls from ADLs. Results indicated that backward falls were characterized by a simultaneous occurrence of a slight increase in trunk extension angle (average peak = 11°) and a dramatic increase in extension angular velocity (average peak = 139.7°/s). It was concluded that trunk angular kinematics could be used to design an effective fall detector.

Changes In Upper Extremity And Trunk Angular Kinematics During Power-assisted Wheelchair Use

Two types of wheelchairs have traditionally been available to the public: manual and power. Pushrim-activated power-assisted wheels (PAWs) are an intermediate alternative. Changes in upper extremity and trunk kinematics while using PAWs have not been thoroughly explored. PURPOSE: To determine if PAWs influence upper extremity and trunk angular kinematics after prolonged use and across different surfaces. METHODS: Thirteen male and six female full-time manual wheelchair users (age 43.1±15.0 yrs) who had no musculoskeletal disorders in their upper extremities participated. Each participant was fitted with reflective markers on their upper extremities and trunk. Each participant wheeled over three different surfaces at a self-selected pace: a flat vinyl floor, a thick carpet, and a 4m long ramp inclined to 6 degrees. Kinematic data were collected during four separate visits: S1 (participants used their own manual wheelchair), S2 (participants used their own wheelchair fitted with PAWs after a few minutes of practice), S3 (participants were tested after 8 weeks of PAW use), and S4 (participants returned to their own wheelchair for 4 weeks). Each trial was recorded using seven digital cameras. Angular kinematics of the trunk (flex/ext), shoulder (flex/ext and ab/aduction), elbow (flex/ext), and wrist (flex/ext) were calculated. RESULTS: Separate two-way ANOVA (time x surface) indicated that participants utilized less elbow flexion in S3 compared to S1 and S4 (see table). As expected, wheeling up the ramp increased angular demands on the upper extremities. CONCLUSIONS: The results indicate that wheelers utilize less elbow flexion during the recovery phase after prolonged PAW use. This difference may have clinical significance.TABLE: No caption avaialable.

Multi-segment trunk kinematics during a loaded lifting task for elderly and young subjects

The trunk is frequently modelled as one fixed segment ignoring possible multi-segmental contributions during manual handling. This study compared segmental trunk motion in a young and older population during a lifting task. Twelve elderly and 19 young subjects repeatedly lifted a 5 kg box from bench to shelf under two stance conditions. Displacement and angular trunk segment kinematics were recorded with an electromagnetic tracker system and then analysed. The elderly subjects displayed significantly increased pelvic and trunk displacement and significantly reduced pelvic and lower thorax (T10–L1) range of motion in both stance conditions. Upper thorax (C7–T10) motion was at times greater than lumbar motion and opposite to the lower segments and was related to the task while the lower segments contributed to both equilibrium and task requirements. Decreased segmental trunk angular kinematics may contribute to increased displacement kinematics and place the elderly at increased risk of injury and falling. The pelvis, lumbar spine, low thorax (T10–L1), upper thorax (C7–10) contributed uniquely and synchronously to trunk (C7–S2) mechanics during a lifting task. Reduced angular kinematics of the pelvis and low thorax contributed to increased displacement kinematics and hence increased the risk of falling in the elderly compared to the young. Investigations of trunk mechanics should include multi-segment analysis.

Is the trunk movement more perturbed after an asymmetric than after a symmetric perturbation during lifting?

Low back injury is associated with sudden movements and loading. Trunk motion after sudden loading depends on the stability of the spine prior to loading and on the trunk muscle activity in response to the loading. Both factors are not axis-symmetric. Therefore, it was hypothesized that the effects on trunk dynamics would be larger after an asymmetric than after a symmetric perturbation. Ten subjects lifted a crate in which, prior to lifting, a mass was displaced to the front or to the side without the subjects being aware of this. Crate and subject movements, crate reaction forces and muscle activity were recorded. From this, the stability prior to the perturbation was estimated, and the trunk angular kinematics and moments at the lumbo-sacral joint were calculated. Both perturbations only minimally affected the trunk kinematics, although the stability of the spine prior to the lifting movement was higher in the sagittal plane than in the frontal plane. In both conditions the stability appeared to be sufficient to absorb the applied perturbation.

Is the trunk movement more perturbed after an asymmetric than after a symmetric perturbation during lifting?

Low back injury is associated with sudden movements and loading. Trunk motion after sudden loading depends on the stability of the spine prior to loading and on the trunk muscle activity in response to the loading. Both factors are not axis-symmetric. Therefore, it was hypothesized that the effects on trunk dynamics would be larger after an asymmetric than after a symmetric perturbation. Ten subjects lifted a crate in which, prior to lifting, a mass was displaced to the front or to the side without the subjects being aware of this. Crate and subject movements, crate reaction forces and muscle activity were recorded. From this, the stability prior to the perturbation was estimated, and the trunk angular kinematics and moments at the lumbo-sacral joint were calculated. Both perturbations only minimally affected the trunk kinematics, although the stability of the spine prior to the lifting movement was higher in the sagittal plane than in the frontal plane. In both conditions the stability appeared to be sufficient to absorb the applied perturbation.