Inter-individual variability in a repetitive lifting task

2021 ◽  
Vol 65 (1) ◽  
pp. 833-837
Author(s):  
Emmanuel Tetteh ◽  
Pramiti Sarker ◽  
Colten Fales ◽  
Jeff Mettler ◽  
Gary Mirka
Keyword(s):  
Range Of Motion ◽  
Injury Risk ◽  
Transverse Velocity ◽  
Individual Variability ◽  
Low Back ◽  
Repetitive Lifting ◽  
Biomechanical Loading ◽  
Homogeneity Of Variance ◽  
Trunk Kinematics ◽  
Lifting Task

Trunk kinematics directly impact the biomechanical loading of the tissues of the low back. Quantifying the variability in trunk kinematics may provide deeper insights into biomechanical loading and low back injury risk. Inter-lifter variability in trunk kinematics was assessed as twenty participants performed a repetitive lifting task at three levels of the NIOSH Lifting Index. Trunk kinematics were captured and Levene’s test of homogeneity of variance was used to test the hypothesis that variance in kinematic parameters increased as a function of level of lifting index. Results showed considerable levels of variability in all kinematics parameters, and for sagittal range of motion, mean sagittal velocity, transverse range of motion, and mean transverse velocity the variance was significantly affected (p<0.05) by level of lifting index. The results of this study demonstrate that variability (both inter- and intra-lifter) should be considered as one considers the relative risk of a lifting task.

Effect of Load Weight and Starting Height on the Variability of Trunk Kinematics

2018 ◽  
Vol 62 (1) ◽  
pp. 905-909 ◽  
Author(s):  
Hamid Norasi ◽  
Jordyn Koenig ◽  
Gary Mirka
Keyword(s):  
Sagittal Plane ◽  
Transverse Plane ◽  
Low Back ◽  
Trunk Motion ◽  
Repetitive Lifting ◽  
Low Back Injuries ◽  
Trunk Kinematics ◽  
Lifting Task ◽  
Dominant Parameter ◽  
Load Weight

Trunk kinematic variables have been used to understand the risk of low back injuries in the workplace. Variability in trunk kinematics has not been explored to the same level. In the current study, it was hypothesized that workplace variables (starting height and load weight) would have an impact on the variability in the kinematic variables describing trunk motion. Ten participants performed a repetitive lifting task under four different conditions representing two levels of load weight and starting height. The Lumbar Motion Monitor was used to capture key trunk kinematic variables from the concentric range of lifting motion. The dominant parameter in this experiment was found to be the starting height of the lift which significantly affected the variability of trunk kinematics in sagittal plane. In the transverse plane neither starting height of the load nor the weight of the load were found to influence the variability of trunk kinematics significantly.

The Effects of Box Differences and Employee Job Experience on Trunk Kinematics & Low Back Injury Risk during Depalletizing Operations

1996 ◽  
Vol 40 (13) ◽  
pp. 651-655 ◽  
Author(s):  
W. Gary Allread ◽  
William S. Marras ◽  
Kevin P. Granata ◽  
Kermit G. Davis ◽  
Michael J. Jorgensen
Keyword(s):  
Injury Risk ◽  
Risk Model ◽  
Food Distribution ◽  
Low Back ◽  
Job Experience ◽  
Work Related ◽  
Back Disorder ◽  
Trunk Kinematics ◽  
Different Characteristics ◽  
Main Effects

Workers from a local food distribution center were studied depalletizing boxes from a pallet. The objectives of this study were to determine the change in trunk kinematics associated with selecting boxes having different characteristics and to observe if there was a relationship between trunk kinematics and employee job experience. The boxes varied in terms of: size; presence/absence of handles; weight; and location on a pallet. Worker job experience also was recorded. Kinematic trunk motions and subsequent risk of low back disorder (LBD), assessed using a risk model, were studied as dependent measures. Results indicated that the weight and layer conditions influenced most of the kinematic variables. The size and handle conditions influenced fewer dependent measures. All main effects but the handle condition had an influence on LBD risk. Most of the significant interaction effects were related to layer, illustrating the tremendous influence that box location on a pallet had on trunk kinematics and LBD risk. In fact, at the bottom pallet layers, LBD risk was the same regardless of the weight lifted or the size of the box. In studying job experience, inexperienced workers were found to have LBD risk values that were, on average, 5% higher than the experienced group. This study has been successful at pinpointing which box parameters are worthy of consideration to include in a food distribution environment for the purposes of reducing the risk of work-related LBD.

Effect of Time on the Variability of Lifting Kinematics in a Repetitive Lifting Task

2018 ◽  
Vol 62 (1) ◽  
pp. 910-914
Author(s):  
Emmanuel Tetteh ◽  
Gary Mirka
Keyword(s):  
Body Weight ◽  
The Other ◽  
Downward Trend ◽  
Low Back ◽  
Time Intervals ◽  
Repetitive Lifting ◽  
Lifting Kinematics ◽  
Lifting Task ◽  
Over Time ◽  
Lumbar Motion

A repetitive lifting task affords the opportunity for lift-to-lift variability in the lifting strategy and kinematics which can result in changes in the stresses on the tissues of the low back. To quantify the variation of lifting kinematics over time, ten subjects were recruited to perform repetitive lifting of a load equal to 10% of body weight at a rate of six lifts/min for 30 minutes continuously. Trunk kinematic variables were measured in all three planes of motion using the Lumbar Motion Monitor. The variances of the lifting kinematics were compared for the following ten-minute intervals: 0-10 min, 10-20 min and 20-30 min. Time was found to have a significant impact on variance of the peak sagittal acceleration, with the variance seen in the first ten minutes exceeding that of the other two time intervals. The downward trend in variation of peak sagittal acceleration implies an initial adjustment as the lifters “settle in” to their preferred lifting strategy.

scholarly journals How Does Self-Efficacy Influence Pain Perception, Postural Stability and Range of Motion in Individuals with Chronic Low Back Pain?

2019 ◽  
Vol 1 (22;1) ◽  
pp. E1-E13 ◽  
Author(s):  
Roy La Touche
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Range Of Motion ◽  
Self Efficacy ◽  
Postural Stability ◽  
Temporal Summation ◽  
Pain Catastrophizing ◽  
Low Back ◽  
Lumbar Range Of Motion ◽  
Lifting Task

Background: Low back pain (LBP) is the most prevalent musculoskeletal problem among adults. Individuals with chronic LBP (CLBP) can present a psychological disorder and a lack of pain self-efficacy. Objectives: The objective of this study was to compare the process of repetition-induced summation of activity-related pain, the lumbar range of motion, and the postural stability of patients with non-specific LBP (NSLBP) based on their level of self-efficacy. Study Design: This research used a descriptive, cross-sectional study design. Methods: This research included 60 patients with NSCLBP. Patients were classified as having “high” or “low” self-efficacy based on a median split of scores on the Chronic Pain Self-Efficacy Scale. All patients received a sociodemographic questionnaire, a psychological self-reported measures (Tampa scale of Kinesiophobia; Pain Catastrophizing Scale; Rumination subscale, Magnification subscale; Helplessness subscale; Roland-Morris Disability Questionnaire; FearAvoidance Belief Questionnaire; Physical Activity subscale; Work subscale); and completed the Temporal Summation Lifting Task, Lumbar Range of Motion, and Multi-Directional Functional Reach Test (MDFRT). Results: The results indicated that the low self-efficacy group had a shorter lumbar range of motion and lower postural stability, in addition to greater pain intensity in the temporal summation lifting task, compared with the high self-efficacy group. The analysis showed that the strongest correlation for the high self-efficacy was between fear of movement and the temporal summation lifting task, and greater scores at the psychological questionnaires, compared with the high selfefficacy group (r = 0.711; P < 0.01). The strongest correlations found for the low self-efficacy group, showed a positive relationship between pain catastrophizing and the temporal summation lifting task (r = 0.765; P < 0.01), and a strong negative association between pain catastrophizing for the magnification subscale and lumbar range of motion (r = -0.759; P < 0.01). Limitations: The results of this study should be interpreted with caution because of its crosssectional design, and therefore causal relationships cannot be established. A significant limitation of the study is that patients’ physical activity levels were not assessed, which could have influenced their ability to perform motor tasks at the perceived difficulty and fear level. Conclusions: The high self-efficacy group had less pain in the temporal summation lifting task, a greater range of motion, and a greater functional range, in addition to a lower influence of psychological factors. Key words: Low back pain, chronic pain, self-efficacy, temporal summation, range of motion, postural stability, fear of movement, pain catastrophizing, low back disability

Ergonomic Assessment of Low Back Loading Pattern During Occupational Lifting Task in a Lower Limb Amputee: Minimizing Injury Risk.

2020 ◽  
Vol 64 (1) ◽  
pp. 1466-1470
Author(s):  
Chandrasekaran Jayaraman ◽  
Chaithanya K. Mummidisetty ◽  
Shenan Hoppe-Ludwig ◽  
Matthew McGuire ◽  
Arun Jayaraman
Keyword(s):  
Lower Limb ◽  
Injury Risk ◽  
Muscle Activation ◽  
Compressive Force ◽  
Sensor Data ◽  
Healthy Population ◽  
Low Back ◽  
Muscle Activation Patterns ◽  
Lower Limb Amputee ◽  
Lifting Task

While the relationship between occupational task intensity and repetitive overuse injuries have been well studied and prescription/guidelines to assess and minimize risk of such injuries well established in the general healthy population, these aspects are not well understood in individuals with disabilities. In this practice-oriented paper, we use high a resolution sensor-data driven methodology to track muscle activation patterns and joint kinematics during a common lifting task in a unilateral lower limb amputee to gain a better understanding of the risk of injury during non-optimal lifting postures. The observed data from high resolution sensors are used to recommend optimized prosthetic device tuning. Further the participant specific low back compression loads calculated using Hand-Calculation Back Compressive Force estimation model (HCBCF) and the University of Michigan 3D Static Strength Prediction Program (3DSSPP™) model is used to identify the safe zones of joint loading during the lifting task.

scholarly journals Analyzing the Magnitude of Interlimb Asymmetries in Young Female Soccer Players: A Preliminary Study

2021 ◽  
Vol 18 (2) ◽  
pp. 475
Author(s):  
Javier Raya-González ◽  
Filipe Manuel Clemente ◽  
Daniel Castillo
Keyword(s):  
Range Of Motion ◽  
Muscle Mass ◽  
Injury Risk ◽  
Young Female ◽  
Asymmetry Index ◽  
Lower Limbs ◽  
Soccer Players ◽  
Countermovement Jump ◽  
Change Of Direction ◽  
Jump Ability

Although asymmetries in lower limbs have been linked with players’ performance in male soccer players, literature that has been published addressing female soccer is scarce. Thus, the aim of this study was twofold: (i) describe the asymmetries of women soccer players during jumping, change-of-direction and range-of-motion tests; and (ii) test possible relationships between asymmetries and injury risk in female soccer players. Sixteen female players (15.5 ± 1.5 years) performed a battery of fitness tests (i.e., jump ability, change-of-direction ability and passive range-of-motion) and muscle mass analysis via dual-energy X-ray absorptiometry, through which the specific asymmetry index and the related injury risk were calculated. Significant (p < 0.05) lower asymmetries in the change-of-direction test were observed in comparison to those observed in jumping and range-of-motion tests; significant (p < 0.05) lower asymmetries in muscle mass were also reported compared to those found in the change-of-direction and countermovement jump tests. Additionally, increased injury risk for countermovement jump and hip flexion with extended knee range-of-motion (relating to asymmetry values) and for ankle flexion with flexed knee range-of-motion in both legs (relating to reference range-of-motion values), as well as increased individual injury risk values, were observed across all tests. These findings suggest the necessity to implement individual approaches for asymmetry and injury risk analyses.

scholarly journals Modelling the Additivity of Perceived Exertion in Symmetric, Mid-Sagittal Lifting

1994 ◽  
Vol 38 (10) ◽  
pp. 621-625 ◽  
Author(s):  
Brian D. Lowe
Keyword(s):  
Perceived Exertion ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Whole Body ◽  
Coefficient Of Determination ◽  
Perceived Effort ◽  
Repetitive Lifting ◽  
The Relationship ◽  
Whole Body Exertion ◽  
Lifting Task

Psychophysical approaches to quantifying perceived effort have been used to evaluate the physical demand of many industrial work activities. An experiment was conducted to examine the relationship between ratings of whole-body perceived exertion and differentiated, regional ratings of exertion. The Borg, CR-10 scale was used by 16 subjects performing a simulated repetitive lifting task. Ratings of perceived exertion were obtained for the arms, legs, torso, and central (cardiorespiratory) effort sensations as well as a rating of overall, whole-body exertion. A multiple linear regression analysis was used to predict the whole-body rating of exertion from the differentiated ratings in lifting tasks using both a squat and stoop posture. In the stoop posture condition the coefficient of determination between whole-body perceived exertion and the model including arm, torso, and central ratings was R2=0.81. In the squat posture condition, the final regression model predicting whole-body exertion contained only the rating from the legs (R2 = 0.62). Differentiated ratings explained the majority of the variance in whole-body perceived exertion for squat and stoop lifting tasks.

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