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Larson DJ, Brown SHM. Effects of trunk extensor muscle fatigue on repetitive lift (re)training using an augmented tactile feedback approach. ERGONOMICS 2023; 66:1919-1934. [PMID: 36636970 DOI: 10.1080/00140139.2023.2168769] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
Augmented tactile and performance feedback has been used to (re)train a modified lifting technique to reduce lumbar spine flexion, which has been associated with low back disorder development during occupational repetitive lifting tasks. However, it remains unknown if the presence of trunk extensor neuromuscular fatigue influences learning of this modified lifting technique. Therefore, we compared the effectiveness of using augmented tactile and performance feedback to reduce lumbar spine flexion during a repetitive lifting task, in both unfatigued and fatigued states. Participants completed repetitive lifting tests immediately before and after training, and 1-week later, with half of the participants completing training after fatiguing their trunk extensor muscles. Both groups demonstrated learning of the modified lifting technique as demonstrated by increased thorax-pelvis coordination variability and reduced lumbar range of motion variability; however, experiencing trunk extensor neuromuscular fatigue during lift (re)training may have slight negative influences on learning the modified lifting technique. Practitioner summary: An augmented lift (re)training paradigm using tactile cueing and performance feedback regarding key movement features (i.e. lumbar spine flexion) can effectively (re)train a modified lifting technique to reduce lumbar flexion and redistribute motion to the hips and knees. However, performing (re)training while fatigued could slightly hinder learning this lifting technique.
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Affiliation(s)
- Dennis J Larson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Stephen H M Brown
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
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Blomeyer N, Tandale SB, Nicolini LF, Kobbe P, Pufe T, Markert B, Stoffel M. Prediction of Temperature and Loading History Dependent Lumbar Spine Biomechanics Under Cyclic Loading Using Recurrent Neural Networks. Ann Biomed Eng 2023; 51:1244-1255. [PMID: 36709233 PMCID: PMC10172265 DOI: 10.1007/s10439-022-03128-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 12/25/2022] [Indexed: 01/30/2023]
Abstract
Extended-duration cyclic loading of the spine is known to be correlated to lower back pain (LBP). Therefore, it is important to understand how the loading history affects the entire structural behavior of the spine, including the viscoelastic effects. Six human spinal segments (L4L5) were loaded with pure moments up to 7.5 Nm cyclically for half an hour, kept unloaded for 15 min, and loaded with three cycles. This procedure was performed in flexion-extension (FE), axial rotation (AR), and lateral bending (LB) and repeated six times per direction for a total of 18 h of testing per segment. A Long Short-Term Memory (LSTM) Recurrent Neural Network (RNN) was trained to predict the change in the biomechanical response under cyclic loading. A strong positive correlation between the total testing time and the ratio of the third cycle to the last cycle of the loading sequence was found (BT: [Formula: see text] = 0.3469, p = 0.0003, RT: [Formula: see text] =0.1988, p = 0.0377). The moment-range of motion (RoM) curves could be very well predicted with an RNN ([Formula: see text]=0.988), including the correlation between testing time and testing temperature as inputs. This study shows successfully the feasibility of using RNNs to predict changing moment-RoM curves under cyclic moment loading.
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Affiliation(s)
- Nadja Blomeyer
- Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstr. 18, 52062, Aachen, Germany.
| | | | - Luis Fernando Nicolini
- Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstr. 18, 52062, Aachen, Germany.,Department of Trauma and Reconstructive Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Philipp Kobbe
- Department of Trauma and Reconstructive Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Thomas Pufe
- Department of Anatomy and Cell Biology, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Bernd Markert
- Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstr. 18, 52062, Aachen, Germany
| | - Marcus Stoffel
- Institute of General Mechanics, RWTH Aachen University, Eilfschornsteinstr. 18, 52062, Aachen, Germany
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3
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The Effects of an Acute Maximal Seated Lumbar Spine Flexion Exposure on Low Back Mechanical Pain Sensitivity. J Appl Biomech 2022; 38:12-19. [PMID: 34969008 DOI: 10.1123/jab.2021-0238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/01/2021] [Accepted: 10/27/2021] [Indexed: 11/18/2022]
Abstract
Viscoelastic creep generated in the lumbar spine following sustained spine flexion may affect the relationship between tissue damage and perceived pain. Two processes supporting this altered relationship include altered neural feedback and inflammatory processes. Our purpose was to determine how low back mechanical pain sensitivity changes following seated lumbar spine flexion using pressure algometry in a repeated-measures, cross-sectional laboratory design. Thirty-eight participants underwent a 10-minute sustained seated maximal flexion exposure with a 40-minute standing recovery period. Pressure algometry assessed pressure pain thresholds and the perceived intensity and unpleasantness of fixed pressures. Accelerometers measured spine flexion angles, and electromyography measured muscular activity during flexion. The flexion exposure produced 4.4° (2.7°) of creep that persisted throughout the entire recovery period. The perception of low back stimulus unpleasantness was elevated immediately following the exposure, 20 minutes before a delayed increase in lumbar erector spinae muscle activity. Women reported the fixed pressures to be more intense than men. Sustained flexion had immediate consequences to the quality of mechanical stimulus perceived but did not alter pressure pain thresholds. Neural feedback and inflammation seemed unlikely mechanisms for this given the time and direction of pain sensitivity changes, leaving a postulated cortical influence.
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Viggiani D, Callaghan JP. Interrelated hypoalgesia, creep, and muscle fatigue following a repetitive trunk flexion exposure. J Electromyogr Kinesiol 2021; 57:102531. [PMID: 33607359 DOI: 10.1016/j.jelekin.2021.102531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 12/31/2020] [Accepted: 02/05/2021] [Indexed: 11/29/2022] Open
Abstract
Repetitive trunk flexion can damage spinal tissues, however its association with low back pain in the workplace may be confounded by factors related to pain sensitivity. Muscle fatigue, exercise-induced hypoalgesia, and creep-induced neuromuscular changes following repetitive trunk flexion may all affect this assumed exposure-pain relationship. This study's purpose was to determine how mechanical pain sensitivity in the low back is affected by a repetitive trunk flexion exposure and identify factors associated with changes in low back pain sensitivity. Pressure pain thresholds, perceptions of sub-threshold stimuli, and muscle fatigue in the trunk and tibia, as well as lumbar spine creep were tracked in 37 young healthy adults before and up to 40 min after a 10-min repetitive trunk flexion exposure. Pressure pain thresholds (p = 0.033), but not perceptions of sub-threshold stimuli (p > 0.102) were associated with approximately a 12.5% reduction in pain sensitivity 10 min after completing the exposure, while creep and local muscle fatigue effects were only observed immediately following the exposure. Creep and fatigue interactions and the corresponding tibial measure co-varied with individual low back pressure pain thresholds. The net hypoalgesic effects of repetitive trunk flexion have the potential to partially mask possibly injurious loads, which could contribute to the severity or incidence of lower back injuries related to these exposures.
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Affiliation(s)
- Daniel Viggiani
- Department of Kinesiology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
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Amiri M, Ghomsheh FT, Ghazalian F. Modeling the resistance mechanism of passive knee joint flexion and extension for use in rehabilitation equipment. Proc Inst Mech Eng H 2021; 235:470-479. [PMID: 33482704 DOI: 10.1177/0954411921990133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to model the resistance mechanism of Passive Knee Joint Flexion and Extension to create a similar torque mechanism in rehabilitation equipment. In order to better model the behavior of passive knee tissues, it is necessary to exactly calculate the two coefficients of elasticity of time-independent and time-dependent parts. Ten healthy male volunteers (mean height 176.4+/-4.59 cm) participated in this study. Passive knee joint flexion and extension occurred at velocities of 15, 45, and 120 (degree/s), and in five consecutive cycles and within the range of 0 to 100° of knee movement on the sagittal plane on Cybex isokinetic dynamometer. To ensure that the muscles were relaxed, the electrical activity of knee muscles was recorded. The elastic coefficient, (KS) increased with elevating the passive velocity in flexion and extension. The elastic coefficient, (KP) was observed to grow with the passive velocity increase. While, the viscous coefficient (C) diminished with passive velocity rise in extension and flexion. The heightened passive velocity of the motion resulted in increased hysteresis (at a rate of 42%). The desired of passive velocity is lower so that there is less energy lost and the viscoelastic resistance of the tissue in the movement decreases. The Coefficient of Determination, R2 between the model-responses and experimental curves in the extension was 0.96 < R2 < 0.99 and in flexion was 0.95 < R2 < 0.99. This modeling is capable of predicting the true performance of the components of passive knee movement and we can create a resistance mechanism in the rehabilitation equipment to perform knee joint movement. Quantitative measurements of two elastic coefficients of Time-independent and Time-dependent parts passive knee joint coefficients should be used for better accurate simulation the behavior of passive tissues in the knee which is not seen in other studies.
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Affiliation(s)
- Mansoor Amiri
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Farhad Tabatabai Ghomsheh
- Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Farshad Ghazalian
- Department of Physical Education Sport Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
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Vazirian M, Shojaei I, Phillips M, Shapiro R, Bazrgari B. The immediate and prolonged effects of military body armor on the relative timing of thorax and pelvis rotations during toe-touch and two-legged squat tasks. J Biomech 2020; 111:110000. [PMID: 32858429 DOI: 10.1016/j.jbiomech.2020.110000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/03/2020] [Accepted: 08/08/2020] [Indexed: 10/23/2022]
Abstract
Although military body armor is an effective life saver, it considerably loads more weight on the warfighters, increasing the risk of musculoskeletal injury. This study investigated the immediate and prolonged effects of wearing body armor on timing aspect of lumbo-pelvic coordination during the toe-touch (TT) and two-legged-squat (TLS) tests. A cross-over study design was used wherein twelve asymptomatic and gender-balanced individuals completed two experimental sessions with and without body armor. A session included two similar sets of tests, before and after exposure to a treadmill walk, containing a TT and a TLS test with ten cycles of fast bending and return. Reflective markers were attached on the participants to capture the kinematics of body segments in conjunction with a motion capture system. The mean absolute relative phase (MARP) and deviation phase (DP) between the thorax and pelvis were calculated for each test. The pre-walk MARP in the return was significantly larger with versus without body armor (p = 0.022), while there were no significant effects of body armor on the other outcome measures. In addition, the pre-walk MARP and DP in the bending and return, as well as the walk-induced changes in the MARP in the bending phase were significantly larger in TLS versus TT (p < 0.026). Therefore, using a body armor immediately made the lumbo-pelvic coordination less in-phase during return, but no prolonged effects were found. Further investigation is necessary to specify chances wearing a body armor increases the risk of musculoskeletal injuries in the lower back and lower extremities joints.
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Affiliation(s)
- Milad Vazirian
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Iman Shojaei
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Megan Phillips
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Robert Shapiro
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Babak Bazrgari
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
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Larson DJ, Menezes PG, Brown SHM. Influence of creep deformation on sub-regional lumbar spine motion during manual lifting. ERGONOMICS 2020; 63:1304-1311. [PMID: 32452285 DOI: 10.1080/00140139.2020.1774666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Prolonged or repetitive spine flexion induces creep deformation of posterior spine tissues allowing for increased intervertebral motion beyond 'normal' limits, which may influence sub-regional (intersegmental) spine motion during subsequent manual lifting tasks. Using spine skin-surface kinematics, intersegmental lumbar spine motion was recorded over 20 minutes of prolonged static spine flexion and a subsequent manual lifting task (2 lifts every 3 minutes, 30 minutes total) in 14 participants. Results demonstrated that mid to lower lumbar intersegmental levels (i.e. L2/L3 to L4/L5) experienced the greatest overall creep deformation and range of motion during both prolonged flexion and manual lifting; however, overall range of motion during manual lifting was unaffected. Additionally, creep deformation did not completely recover within 30 minutes. Future work should continue to investigate the influence of this residual creep, as well as how overall creep deformation impacts spine neuromuscular control and stability, and ultimately the development of low back disorders. Practitioner summary: Mid to lower lumbar spine levels (i.e. L2/L3 to L4/L5) experienced the greatest creep deformation and range of motion during both prolonged flexion and manual lifting. Repeated lifting following prolonged flexion may limit creep recovery; however, overall lifting kinematic motion remained unchanged.
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Affiliation(s)
- Dennis J Larson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | | | - Stephen H M Brown
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
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Effect of viscoelastic properties on passive torque variations at different velocities of the knee joint extension and flexion movements. Med Biol Eng Comput 2020; 58:2893-2903. [PMID: 32975707 DOI: 10.1007/s11517-020-02247-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/16/2020] [Indexed: 10/23/2022]
Abstract
This study aimed to investigate the rate of passive torque variations of human knee joint in the different velocities of knee flexion and extension movements. Ten healthy men were invited to participate in the tests. All passive torque tests were performed for the knee joint extension and flexion on the sagittal plane in three different angular velocities of 15, 45, and 120°/s; in 5 consecutive cycles; and within 0° to 100° range of motion. The electrical activity of knee joint extensor and flexor muscles was recorded until there was no muscle activity signal. A Three-element Solid Model (SLS) was used to obtain the viscose and elastic coefficients. As the velocity increases, the stretch rate in velocity-independent tissues increases, and the stretch rate in velocity-dependent tissues decreases. By increasing the velocity, the resistance of velocity-dependent parts increases, and the velocity-independent parts are not affected by velocity. Since the first torque that resists the joint movement is passive torque, the elastic and viscous torques should be simultaneously used. It is better to perform the movement at a low velocity so that less energy is lost. The viscoelastic resistance of tissues diminishes. Graphical abstract.
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Khoddam-Khorasani P, Arjmand N, Shirazi-Adl A. Effect of changes in the lumbar posture in lifting on trunk muscle and spinal loads: A combined in vivo, musculoskeletal, and finite element model study. J Biomech 2020; 104:109728. [PMID: 32147242 DOI: 10.1016/j.jbiomech.2020.109728] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 02/23/2020] [Accepted: 02/25/2020] [Indexed: 10/24/2022]
Abstract
Irrespective of the lifting technique (squat or stoop), the lumbar spine posture (more kyphotic versus more lordotic) adopted during lifting activities is an important parameter affecting the active-passive spinal load distribution. The advantages in either posture while lifting remains, however, a matter of debate. To comprehensively investigate the role on the trunk biomechanics of changes in the lumbar posture (lordotic, free or kyphotic) during forward trunk flexion, validated musculoskeletal and finite element models, driven by in vivo kinematics data, were used to estimate detailed internal tissue stresses-forces in and load-sharing among various joint active-passive tissues. Findings indicated that the lordotic posture, as compared to the kyphotic one, resulted in marked increases in back global muscle activities (~14-19%), overall segmental compression (~7.5-46.1%) and shear (~5.4-47.5%) forces, and L5-S1 facet joint forces (by up to 80 N). At the L5-S1 level, the lordotic lumbar posture caused considerable decreases in the moment resisted by passive structures (spine and musculature, ~14-27%), negligible reductions in the maximum disc fiber strains (by ~0.4-4.7%) and small increases in intradiscal pressure (~1.8-3.4%). Collectively and with due consideration of the risk of fatigue and viscoelastic creep especially under repetitive lifts, current results support a free posture (in between the extreme kyphotic and lordotic postures) with moderate contributions from both active and passive structures during lifting activities involving trunk forward flexion.
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Affiliation(s)
- P Khoddam-Khorasani
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - N Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
| | - A Shirazi-Adl
- Division of Applied Mechanics, Department of Mechanical Engineering, Polytechnique Montréal, Québec, Canada
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Mousavi-Khatir R, Talebian S, Toosizadeh N, Olyaei GR, Maroufi N. Disturbance of neck proprioception and feed-forward motor control following static neck flexion in healthy young adults. J Electromyogr Kinesiol 2018; 41:160-167. [PMID: 29935422 DOI: 10.1016/j.jelekin.2018.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/22/2018] [Accepted: 04/23/2018] [Indexed: 11/16/2022] Open
Abstract
The highly complex proprioceptive system provides neuromuscular control of the mobile cervical spine. Static neck flexion can induce the elongation of posterior tissues and altered afferent input from the mechanoreceptors. The purpose of this study was to examine the effect of prolonged static neck flexion on neck proprioception and anticipatory postural adjustments. Thirty-eight healthy participants (20 females and 18 males) between the ages of 20-35 years with no history of neck, low back, and shoulder pain enrolled in this study. Neck proprioception and anticipatory muscle activity were tested before and after 10-min static neck flexion. For assessment of neck proprioception, each participant was asked to perform 10 trials of the cervicocephalic relocation test to the neutral head position after active neck rotation to the left and right sides. Anticipatory postural adjustments were evaluated during a rapid arm flexion test. Following the flexion, the absolute and variable errors in head repositioning significantly increased (p < 0.05). The results also showed that there was a significant delay in the onset of myoelectric activity of the cervical erector spinae muscles after flexion (p = 0.001). The results of this study suggested that a 10-min static flexion can lead to changes in the neck proprioception and feed-forward control due to mechanical and neuromuscular changes in the viscoelastic cervical spine structures. These changes in sensory-motor control may be a risk factor for neck pain and injury.
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Affiliation(s)
- Roghayeh Mousavi-Khatir
- Mobility Impairment Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran; Department of Physical Therapy, School of Rehabilitation, Babol University of Medical Sciences, Babol, Iran.
| | - Saeed Talebian
- Department of Physical Therapy, School of Rehabilitation, Tehran University of Medical Sciences: Pich Shemiran, Tehran, Iran.
| | - Nima Toosizadeh
- Arizona Center on Aging, Department of Medicine, University of Arizona, Tucson, AZ, United States; Department of Biomedical Engineering, University of Arizona, Tucson, AZ, United States.
| | - Gholam Reaza Olyaei
- Department of Physical Therapy, School of Rehabilitation, Tehran University of Medical Sciences: Pich Shemiran, Tehran, Iran.
| | - Nader Maroufi
- Department of Physical Therapy, School of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran
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Mousavi-Khatir R, Talebian S, Toosizadeh N, Olyaei GR, Maroufi N. The effect of static neck flexion on mechanical and neuromuscular behaviors of the cervical spine. J Biomech 2018; 72:152-158. [DOI: 10.1016/j.jbiomech.2018.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 02/25/2018] [Accepted: 03/03/2018] [Indexed: 10/17/2022]
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12
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Weaver TB, Glinka MN, Laing AC. Stooping, crouching, and standing - Characterizing balance control strategies across postures. J Biomech 2017; 53:90-96. [PMID: 28093258 DOI: 10.1016/j.jbiomech.2017.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/02/2016] [Accepted: 01/02/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND While stooping and crouching postures are critical for many activities of daily living, little is known about the balance control mechanisms employed during these postures. Accordingly, the purpose of this study was to characterize the mechanisms driving net center of pressure (COPNet) movement across three postures (standing, stooping, and crouching) and to investigate if control in each posture was influenced by time. METHODS Ten young adults performed the three postures for 60s each. Kinetic signals were collected via a force platform under each foot. To quantify mechanisms of control, correlations (CorrelLR) were calculated between the left and right COP trajectories in the anterior-posterior (AP) and medio-lateral (ML) directions. To examine the potential effects of time on balance control strategies, outcomes during the first 30s were compared to the last 30s. RESULTS CorrelLR values did not differ across postures (AP: p = 0.395; ML: p = 0.647). Further, there were no main effects of time on CorrelLR (AP: p = 0.976; ML: p = 0.105). A significant posture-time interaction was observed in the ML direction (p = 0.045) characterized by 35% decreases in CorrelLR over time for stooping (p = 0.022). CONCLUSION The dominant controllers of sway (i.e., AP: ankle plantar/dorsi flexors; ML: hip load/unload mechanism) are similar across quiet stance stooping, and crouching. Changes in ML control strategies over time suggests that fatigue could affect prolonged stooping more so than crouching or standing.
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Affiliation(s)
- Tyler B Weaver
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Michal N Glinka
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Andrew C Laing
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
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Li CT, Peng YT, Tseng YT, Chen YN, Tsai KH. Comparing the effects of different dynamic sitting strategies in wheelchair seating on lumbar-pelvic angle. BMC Musculoskelet Disord 2016; 17:496. [PMID: 27938365 PMCID: PMC5148897 DOI: 10.1186/s12891-016-1358-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 12/05/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Prolonged static sitting in a wheelchair is associated with an increased risk of lower back pain. The wheelchair seating system is a key factor of this risk because it affects spinal loading in the sitting position. In this study, 7 dynamic sitting strategies (DSSs) are examined: lumbar prominent dynamic sitting (LPDS), back reclined dynamic sitting (BRDS), femur upward dynamic sitting (FUDS), lumbar prominent with back reclined dynamic sitting (LBDS), lumbar prominent with femur upward dynamic sitting (LFDS), back reclined with femur upward dynamic sitting (BFDS), and lumbar prominent with back reclined with femur upward dynamic sitting (LBFDS). The objective of this study was to analyze the biomechanical effects of these sitting strategies on lumbar-pelvic angles. METHODS Twenty able-bodied participants were recruited for the study. All participants performed LPDS, BRDS, FUDS, LBDS, LFDS, BFDS, and LBFDS in a random order. All lumbar-pelvic angle parameters, including the static lumbar angle, static pelvic angle, lumbar range of motion, and pelvic range of motion were measured and compared. RESULTS Results show that LBDS and LBFDS enabled the most beneficial lumbar movements, although the difference between the 2 strategies was nonsignificant. BRDS and BFDS enabled the most beneficial pelvic movements, although the difference between the 2 strategies was nonsignificant. Among all the upright DSSs, LPDS and LFDS enabled the most beneficial lumbar and pelvic movements, although no significant difference was observed between these 2 strategies. CONCLUSIONS We identified the effects and differences among 7 DSSs on lumbar-pelvic angles. Wheelchair users can choose the most suitable DSS that meets their needs. These findings may serve as a reference for practicing physicians or wheelchair users to choose an appropriate dynamic wheelchair seating system. TRIAL REGISTRATION ISRCTN12389808 , 18th November 2016, retrospectively registered.
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Affiliation(s)
- Chun-Ting Li
- Graduate Institute of Mechatronic System Engineering, National University of Tainan, No. 33, Sec. 2, Shu-Lin St., West Central Dist., Tainan City, 70005, Taiwan
| | - Yao-Te Peng
- Department of BioMedical Engineering, National Cheng Kung University, No.1, University Rd., East Dist., Tainan City, 70101, Taiwan
| | - Yen-Ting Tseng
- Graduate Institute of Mechatronic System Engineering, National University of Tainan, No. 33, Sec. 2, Shu-Lin St., West Central Dist., Tainan City, 70005, Taiwan.,Center of Excellence for Diagnostic Products, Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, No. 195, Sec. 4, Chung-Hsing Rd., Chutung Township, Hsinchu County, 31040, Taiwan
| | - Yen-Nien Chen
- Department of BioMedical Engineering, National Cheng Kung University, No.1, University Rd., East Dist., Tainan City, 70101, Taiwan.
| | - Kuen-Horng Tsai
- Graduate Institute of Mechatronic System Engineering, National University of Tainan, No. 33, Sec. 2, Shu-Lin St., West Central Dist., Tainan City, 70005, Taiwan.
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Voglar M, Wamerdam J, Kingma I, Sarabon N, van Dieën JH. Prolonged Intermittent Trunk Flexion Increases Trunk Muscles Reflex Gains and Trunk Stiffness. PLoS One 2016; 11:e0162703. [PMID: 27768688 PMCID: PMC5096890 DOI: 10.1371/journal.pone.0162703] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 08/27/2016] [Indexed: 02/03/2023] Open
Abstract
The goal of the present study was to determine the effects of prolonged, intermittent flexion on trunk neuromuscular control. Furthermore, the potential beneficial effects of passive upper body support during flexion were investigated. Twenty one healthy young volunteers participated during two separate visits in which they performed 1 hour of intermittent 60 seconds flexion and 30 seconds rest cycles. Flexion was set at 80% lumbar flexion and was performed with or without upper body support. Before and after intermittent flexion exposure, lumbar range of motion was measured using inertial measurement units and trunk stability was assessed during perturbations applied in the forward direction with a force controlled actuator. Closed-loop system identification was used to determine the trunk translational admittance and reflexes as frequency response functions. The admittance describes the actuator displacement as a function of contact force and to assess reflexes muscle activation was related to actuator displacement. Trunk admittance gain decreased after unsupported flexion, while reflex gain and lumbar range of motion increased after both conditions. Significant interaction effects confirmed a larger increase in lumbar range of motion and reflex gains at most frequencies analysed following unsupported flexion in comparison to supported flexion, probably compensating for decreased passive tissue stiffness. In contrast with some previous studies we found that prolonged intermittent flexion decreased trunk admittance, which implies an increase of the lumped intrinsic and reflexive stiffness. This would compensate for decreased stiffness at the cost of an increase in cumulative low back load. Taking into account the differences between conditions it would be preferable to offer upper body support during activities that require prolonged trunk flexion.
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Affiliation(s)
- Matej Voglar
- University of Primorska, Andrej Marušič Institute, Koper, Slovenia
| | - Jeffrey Wamerdam
- MOVE Research Institute Amsterdam, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Idsart Kingma
- MOVE Research Institute Amsterdam, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Nejc Sarabon
- University of Primorska, Andrej Marušič Institute, Koper, Slovenia.,S2P Ltd., Laboratory for Motor Control and Motor Learning, Ljubljana, Slovenia
| | - Jaap H van Dieën
- MOVE Research Institute Amsterdam, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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15
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Mousavi-Khatir R, Talebian S, Maroufi N, Olyaei GR. Effect of static neck flexion in cervical flexion-relaxation phenomenon in healthy males and females. J Bodyw Mov Ther 2016; 20:235-42. [DOI: 10.1016/j.jbmt.2015.07.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 06/23/2015] [Accepted: 07/22/2015] [Indexed: 11/25/2022]
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16
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Viscoelastic Response of the Human Lower Back to Passive Flexion: The Effects of Age. Ann Biomed Eng 2016; 44:2817-26. [PMID: 26883956 DOI: 10.1007/s10439-016-1569-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/10/2016] [Indexed: 01/07/2023]
Abstract
Low back pain is a leading cause of disability in the elderly. The potential role of spinal instability in increasing risk of low back pain with aging was indirectly investigated via assessment of age-related differences in viscoelastic response of lower back to passive deformation. The passive deformation tests were conducted in upright standing posture to account for the effects of gravity load and corresponding internal tissues responses on the lower back viscoelastic response. Average bending stiffness, viscoelastic relaxation, and dissipated energy were quantified to characterize viscoelastic response of the lower back. Larger average bending stiffness, viscoelastic relaxation and dissipated energy were observed among older vs. younger participants. Furthermore, average bending stiffness of the lower back was found to be the highest around the neutral standing posture and to decrease with increasing the lower back flexion angle. Larger bending stiffness of the lower back at flexion angles where passive contribution of lower back tissues to its bending stiffness was minimal (i.e., around neutral standing posture) highlighted the important role of active vs. passive contribution of tissues to lower back bending stiffness and spinal stability. As a whole our results suggested that a diminishing contribution of passive and volitional active subsystems to spinal stability may not be a reason for higher severity of low back pain in older population. The role of other contributing elements to spinal stability (e.g., active reflexive) as well as equilibrium-based parameters (e.g., compression and shear forces under various activities) in increasing severity of low back pain with aging should be investigated in future.
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17
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Boocock MG, Mawston GA, Taylor S. Age-related differences do affect postural kinematics and joint kinetics during repetitive lifting. Clin Biomech (Bristol, Avon) 2015; 30:136-43. [PMID: 25576019 DOI: 10.1016/j.clinbiomech.2014.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 11/19/2014] [Accepted: 12/19/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND Age is considered a risk factor for manual handling-related injuries and older workers incur higher injury-related costs than younger co-workers. This study investigated the differences between the kinematics and kinetics of repetitive lifting in two groups of handlers of different ages. METHODS Fourteen younger (mean 24.4 yr) and 14 older (mean 47.2 yr) males participated in the study. Participants repetitively lifted a box weighing 13 kg at a frequency of 10 lifts/min for a maximum of 20 min. Postural kinematics (joint and lumbosacral angles and angular velocities) and kinetics (joint moments) were measured throughout the lifting task using motion analysis and ground reaction forces. Muscle fatigue of the erector spinae was assessed using electromyography. FINDINGS Peak lumbosacral, trunk, hip and knee flexion angles differed significantly between age groups over the duration of the task, as did lumbosacral and trunk angular velocities. The younger group increased peak lumbar flexion by approximately 18% and approached 99% of maximum lumbosacral flexion after 20 min, whereas the older group increased lumbar flexion by 4% and approached 82% maximum flexion. The younger group had a larger increase in peak lumbosacral and trunk angular velocities during extension, which may be related to the increased back muscle fatigue observed among the younger group. INTERPRETATION Older participants appeared to control the detrimental effects of fatigue associated with repetitive lifting and limit lumbar spine range of motion. The higher rates of musculoskeletal injury among older workers may stem from a complex interaction of manual handling risk factors.
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Affiliation(s)
- Mark G Boocock
- Health and Rehabilitation Research Institute, Auckland University of Technology, New Zealand.
| | - Grant A Mawston
- Health and Rehabilitation Research Institute, Auckland University of Technology, New Zealand
| | - Steve Taylor
- Health and Rehabilitation Research Institute, Auckland University of Technology, New Zealand
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