scholarly journals Muscle Contributions to L4-5 Joint Rotational Stiffness following Sudden Trunk Flexion and Extension Perturbations

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Joel A. Cort ◽  
James P. Dickey ◽  
Jim R. Potvin
Keyword(s):  
Feedback System ◽  
Erector Spinae ◽  
Joint Stability ◽  
Trunk Flexion ◽  
Rotational Stiffness ◽  
Robotic Platform ◽  
Neuromuscular Responses ◽  
Direction Awareness ◽  
Perturbation Direction ◽  
Flexion And Extension

The purpose of this study was to investigate the contribution of individual muscles (MJRSm) to total joint rotational stiffness (MJRST) about the lumbar spine's L4-5 joint prior to, and following, sudden dynamic flexion or extension perturbations to the trunk. We collected kinematic and surface electromyography (sEMG) data while subjects maintained a kneeling posture on a parallel robotic platform, with their pelvis constrained by a harness. The parallel robotic platform caused sudden inertial trunk flexion or extension perturbations, with and without the subjects being aware of the timing and direction. Prevoluntary muscle forces incorporating both short and medium latency neuromuscular responses contributed significantly to joint rotational stiffness, following both sudden trunk flexion and extension motions. MJRST did not change with perturbation direction awareness. The lumbar erector spinae were always the greatest contributor to MJRST. This indicates that the neuromuscular feedback system significantly contributed to MJRST, and this behaviour likely enhances joint stability following sudden trunk flexion and extension perturbations.

Timing of Activation of the Erector Spinae and Hamstrings During a Trunk Flexion and Extension Task

Spine ◽  
2001 ◽  
Vol 26 (4) ◽  
pp. 418-425 ◽  
Author(s):  
Raymond W. McGorry ◽  
Simon M. Hsiang ◽  
Fadi A. Fathallah ◽  
Edward A. Clancy
Keyword(s):  
Erector Spinae ◽  
Trunk Flexion ◽  
Flexion And Extension

scholarly journals Using a Back Exoskeleton During Industrial and Functional Tasks—Effects on Muscle Activity, Posture, Performance, Usability, and Wearer Discomfort in a Laboratory Trial

2021 ◽  
pp. 001872082110072
Author(s):  
Tessy Luger ◽  
Mona Bär ◽  
Robert Seibt ◽  
Monika A. Rieger ◽  
Benjamin Steinhilber
Keyword(s):  
Heart Rate ◽  
Muscle Activity ◽  
Vastus Lateralis ◽  
Erector Spinae ◽  
Stair Climbing ◽  
Trunk Flexion ◽  
User Friendliness ◽  
Timed Up And Go ◽  
System Usability Scale ◽  
Task Accomplishment

Objective To investigate the effect of using a passive back-support exoskeleton (Laevo V2.56) on muscle activity, posture, heart rate, performance, usability, and wearer comfort during a course of three industrial tasks (COU; exoskeleton worn, turned-on), stair climbing test (SCT; exoskeleton worn, turned-off), timed-up-and-go test (TUG; exoskeleton worn, turned-off) compared to no exoskeleton. Background Back-support exoskeletons have the potential to reduce work-related physical demands. Methods Thirty-six men participated. Activity of erector spinae (ES), biceps femoris (BF), rectus abdominis (RA), vastus lateralis (VL), gastrocnemius medialis (GM), trapezius descendens (TD) was recorded by electromyography; posture by trunk, hip, knee flexion angles; heart rate by electrocardiography; performance by time-to-task accomplishment (s) and perceived task difficulty (100-mm visual analogue scale; VAS); usability by the System Usability Scale (SUS) and all items belonging to domains skepticism and user-friendliness of the Technology Usage Inventory; wearer comfort by the 100-mm VAS. Results During parts of COU, using the exoskeleton decreased ES and BF activity and trunk flexion, and increased RA, GM, and TD activity, knee and hip flexion. Wearing the exoskeleton increased time-to-task accomplishment of SCT, TUG, and COU and perceived difficulty of SCT and TUG. Average SUS was 75.4, skepticism 11.5/28.0, user-friendliness 18.0/21.0, wearer comfort 31.1 mm. Conclusion Using the exoskeleton modified muscle activity and posture depending on the task applied, slightly impaired performance, and was evaluated mildly uncomfortable. Application These outcomes require investigating the effects of this passive back-supporting exoskeleton in longitudinal studies with longer operating times, providing better insights for guiding their application in real work settings.

scholarly journals Evaluation of Strength and Irradiated Movement Pattern Resulting from Trunk Motions of the Proprioceptive Neuromuscular Facilitation

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Luciana Bahia Gontijo ◽  
Polianna Delfino Pereira ◽  
Camila Danielle Cunha Neves ◽  
Ana Paula Santos ◽  
Dionis de Castro Dutra Machado ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Movement Pattern ◽  
Lower Limbs ◽  
Trunk Flexion ◽  
Average Force ◽  
Proprioceptive Neuromuscular Facilitation ◽  
Muscular Activation ◽  
Flexion And Extension ◽  
Regional Muscle ◽  
Dorsal Flexion

Introduction. The proprioceptive neuromuscular facilitation (PNF) is a physiotherapeutic concept based on muscle and joint proprioceptive stimulation. Among its principles, the irradiation is the reaction of the distinct regional muscle contractions to the position of the application of the motions.Objective. To investigate the presence of irradiated dorsiflexion and plantar flexion and the existing strength generated by them during application of PNF trunk motions.Methods. The study was conducted with 30 sedentary and female volunteers, the PNF motions of trunk flexion, and extension with the foot (right and left) positioned in a developed equipment coupled to the load cell, which measured the strength irradiated in Newton.Results. Most of the volunteers irradiated dorsal flexion in the performance of the flexion and plantar flexion during the extension motion, both presenting an average force of 8.942 N and 10.193 N, respectively.Conclusion. The distal irradiation in lower limbs became evident, reinforcing the therapeutic actions to the PNF indirect muscular activation.

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

2021 ◽  
Author(s):  
Marzyeh Ramezani ◽  
Amin Kordi Yoosefinejad ◽  
Alireza Motealleh ◽  
Mohsen Ghofrani-Jahromi
Keyword(s):  
Erector Spinae ◽  
Relaxation Phenomenon ◽  
Control Group ◽  
Trunk Flexion ◽  
Lumbar Flexion ◽  
Trunk Inclination ◽  
Forward Bending ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation ◽  
Yoga Practitioners

Abstract 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.

A Computer Simulation Study of Fusion Surgery and Artificial Disc Replacement on the Human Cervical Spine

2006 ◽  
Vol 326-328 ◽  
pp. 903-906
Author(s):  
Hyung Soo Ahn ◽  
Il Hyung Park ◽  
Denis DiAngelo
Keyword(s):  
Cervical Spine ◽  
Adjacent Segment ◽  
Artificial Disc ◽  
Spherical Joint ◽  
Rotational Stiffness ◽  
Computer Simulation Study ◽  
Fusion Surgery ◽  
Biomechanical Changes ◽  
Disc Level ◽  
Flexion And Extension

The biomechanical changes brought on by spine fusion and the artificial disc designs to restore physiologic motion were studied by using a cervical spine computer model. Fusion increased the motion compensation at the adjacent segment during flexion and extension. The global rotational stiffness and segmental disc forces were also increased after fusion. Among the three prosthetic disc designs, the PDD-III (5-DOF spherical joint in plane parallel with the C5-C6 disc level) maintained the normal motion and minimized load build up of adjacent segment.

Torque–velocity and power–velocity relationships during isokinetic trunk flexion and extension

2008 ◽  
Vol 23 (5) ◽  
pp. 520-526 ◽  
Author(s):  
Mickaël Ripamonti ◽  
Denis Colin ◽  
Abderrahmane Rahmani
Keyword(s):  
Trunk Flexion ◽  
Flexion And Extension

Differences in lumbopelvic rhythm between trunk flexion and extension

2016 ◽  
Vol 32 ◽  
pp. 274-279 ◽  
Author(s):  
Jie Zhou ◽  
Xiaopeng Ning ◽  
Fadi Fathallah
Keyword(s):  
Trunk Flexion ◽  
Flexion And Extension

Abdominal Muscles Dominate Contributions to Vertebral Joint Stiffness during the Push-up

2008 ◽  
Vol 24 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Samuel J. Howarth ◽  
Tyson A.C. Beach ◽  
Jack P. Callaghan
Keyword(s):  
Lumbar Spine ◽  
Rectus Abdominis ◽  
Erector Spinae ◽  
Abdominal Muscles ◽  
Rotational Stiffness ◽  
Flexion Extension ◽  
External Oblique ◽  
Axial Twist ◽  
Internal Oblique ◽  
Push Up

The goal of this study was to quantify the relative contributions of each muscle group surrounding the spine to vertebral joint rotational stiffness (VJRS) during the push-up exercise. Upper-body kinematics, three-dimensional hand forces and lumbar spine postures, and 14 channels (bilaterally from rectus abdominis, external oblique, internal oblique, latissimus dorsi, thoracic erector spinae, lumbar erector spinae, and multifidus) of trunk electromyographic (EMG) activity were collected from 11 males and used as inputs to a biomechanical model that determined the individual contributions of 10 muscle groups surrounding the lumbar spine to VJRS at five lumbar vertebral joints (L1-L2 to L5-S1). On average, the abdominal muscles contributed 64.32 ± 8.50%, 86.55 ± 1.13%, and 83.84 ± 1.95% to VJRS about the flexion/extension, lateral bend, and axial twist axes, respectively. Rectus abdominis contributed 43.16 ± 3.44% to VJRS about the flexion/extension axis at each lumbar joint, and external oblique and internal oblique, respectively contributed 52.61 ± 7.73% and 62.13 ± 8.71% to VJRS about the lateral bend and axial twist axes, respectively, at all lumbar joints with the exception of L5-S1. Owing to changes in moment arm length, the external oblique and internal oblique, respectively contributed 55.89% and 50.01% to VJRS about the axial twist and lateral bend axes at L5-S1. Transversus abdominis, multifidus, and the spine extensors contributed minimally to VJRS during the push-up exercise. The push-up challenges the abdominal musculature to maintain VJRS. The orientation of the abdominal muscles suggests that each muscle primarily controls the rotational stiffness about a single axis.

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