Use of Kinetic and Kinematic Data to Evaluate Load Transfer as a Mechanism for Flexion Relaxation in the Lumbar Spine

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Samuel J. Howarth ◽  
Paul Mastragostino
Keyword(s):  
Lumbar Spine ◽  
Body Mass ◽  
Full Range ◽  
Added Mass ◽  
Erector Spinae ◽  
Lower Limbs ◽  
Upper Body ◽  
Low Back ◽  
Kinematic Data ◽  
Flexion Relaxation

Flexion relaxation (FR) in the low back occurs when load is transferred from the spine's extensor musculature to its passive structures. This study investigated the influence of added upper body mass on low back kinetics and kinematics at the FR onset. Sixteen participants (eight male, eight female) performed standing full forward spine flexion with 0%, 15%, and 30% of their estimated upper body mass added to their shoulders. Electromyographic data were obtained from the lumbar erector spinae. Ground reaction forces and kinematic data from the lower limbs, pelvis, and spine were recorded. Extensor reaction moments (determined using a bottom-up linked segment model) and flexion angles at the FR onset were documented along with the maximum spine flexion. The angle at the FR onset increased significantly with added mass (p < 0.05). Expressing the FR onset angle as a percent of the full range of trunk flexion motion for that condition negated any differences between the added mass conditions. These findings demonstrate that low back kinetics play a role in mediating FR in the lumbar spine.

scholarly journals Lumbar flexion relaxation phenomenon in the patients with acute and subacute mechanical low back pain and normal subjects

2017 ◽  
Vol 5 (3) ◽  
pp. 1011 ◽  
Author(s):  
Hetal Sanjay Desai ◽  
Rahul Singh Bisen
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Normal Subjects ◽  
Erector Spinae ◽  
Low Back ◽  
Myoelectrical Activity ◽  
Lumbar Flexion ◽  
Erector Spinae Muscle ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation

Background: The purpose is to examine the myoelectrical activity of erector spinae muscle in patients with acute and sub-acute mechanical low back pain (MLBP) and normal subjects.Methods: A total of 30 patients 15 with MLBP and 15 normal subjects of both genders participated in the study with convenient sampling; all were aged between 20-50 years. The participants were asked to perform movement which was paced by computer running a program and the myoelectrical activity of erector spinae muscle in patients with acute and sub-acute mechanical low back pain and normal subjects were examined.Results: This study stated that patients with MLBP has increased or over activity of erector spinae muscle during complete lumbar flexion when the muscle should be electrically silent. This was observed with help of EMG graph where increase in activity was observed with increase in amplitude, duration and time in graph.Conclusions: There is increase in the amplitude, duration and time in flexion relaxation phenomenon (FRP) in mechanical low back pain patients when compared to normal subjects.

Role of the Unperturbed Limb and Arms in the Reactive Recovery Response to an Unexpected Slip During Locomotion

2003 ◽  
Vol 89 (4) ◽  
pp. 1727-1737 ◽  
Author(s):  
Daniel S. Marigold ◽  
Allison J. Bethune ◽  
Aftab E. Patla
Keyword(s):  
Imaging System ◽  
Center Of Mass ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Lower Limbs ◽  
Upper Body ◽  
Recovery Response

Understanding reactive recovery responses to slipping is fundamental in falls research and prevention. The primary purpose of this study was to investigate the role of the unperturbed limb and arms in the reactive recovery response to an unexpected slip. Ten healthy, young adults participated in this experiment in which an unexpected slip was induced by a set of steel free-wheeling rollers. Surface electromyography (EMG) data were collected from the unperturbed limb (i.e., the swing limb) rectus femoris, biceps femoris, tibialis anterior, and the medial head of gastrocnemius, and bilateral gluteus medius, erector spinae, and deltoids. Kinematic data were also collected by an optical imaging system to monitor limb trajectories. The first slip response was significantly different from the subsequent recovery responses to the unexpected slips, with an identifiable reactive recovery response and no proactive changes in EMG patterns. The muscles of the unperturbed limb, upper body, and arms were recruited at the same latency as those previously found for the perturbed limb. The arm elevation strategies assisted in shifting the center of mass forward after it was posteriorly displaced with the slip, while the unperturbed limb musculature demonstrated an extensor strategy supporting the observed lowering of the limb to briefly touch the ground to widen the base of support and to increase stability. Evidently a dynamic multilimb coordinated strategy is employed by the CNS to control and coordinate the upper and lower limbs in reactive recovery responses to unexpected slips during locomotion.

Design of the Second Spine: A Secondary Pathway to Transfer Loads From the Shoulders to the Pelvis

2013 ◽  
Author(s):  
Joon-Hyuk Park ◽  
Paul Stegall ◽  
Damiano Zanotto ◽  
Vineet Vashista ◽  
Xin Jin ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Vertebral Column ◽  
Full Range ◽  
Musculoskeletal Injuries ◽  
Lower Limbs ◽  
Upper Body ◽  
Erect Posture ◽  
Potential Risks ◽  
Muscle Activations ◽  
Backpack Load

The Second Spine is a vest intended to prevent musculoskeletal injuries caused by heavy backpack loads, while also maintaining the range of motion of the wearer. The vest is formed by multiple segments between the shoulder and a pelvic belt. In normal “off” configuration, the segments are disconnected from each other and the vest is flexible providing full range of motion to the upper body. With the pull of a string in the “on” configuration, the vest becomes semi-rigid creating a secondary pathway to transfer loads between the shoulder and a pelvic belt. The device was evaluated by a subject who walked on a treadmill while carrying a backpack load of 25% of his body weight (BW). Experiment results showed that the semi-rigid vest reduces the force exerted on the shoulders and induces a more erect posture. Muscle activations in the lower limbs indicate that loads were successfully transferred from the shoulders to the waist while bypassing the vertebral column. These results show that the device can be used to mitigate potential risks of musculoskeletal injuries caused from backpack loads.

Body Mass, Nonspecific Low Back Pain, and Anatomical Changes in the Lumbar Spine in Judo Athletes

2007 ◽  
Vol 37 (11) ◽  
pp. 688-693 ◽  
Author(s):  
Takashi Okada ◽  
Koichi Nakazato ◽  
Kazunori Iwai ◽  
Masaru Tanabe ◽  
Kazunori Irie ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Lumbar Spine ◽  
Body Mass ◽  
Low Back ◽  
Anatomical Changes ◽  
Judo Athletes

Comparison of Prolonged Rowing on Fixed and Free-floating Ergometers in Competitive Rowers

2018 ◽  
Vol 39 (11) ◽  
pp. 840-845
Author(s):  
Hugo Kerhervé ◽  
Benjamin Chatel ◽  
Sébastien Reboah ◽  
Jérémy Rossi ◽  
Pierre Samozino ◽  
...  
Keyword(s):  
Heart Rate ◽  
Lumbar Spine ◽  
Blood Lactate ◽  
Power Output ◽  
Muscle Activity ◽  
Submaximal Exercise ◽  
Erector Spinae ◽  
Lower Limbs ◽  
Duty Factor ◽  
Stroke Rate

AbstractThis study aimed to compare the effect of a 40-min submaximal rowing exercise performed on ergometers with fixed and free-floating designs. Heart rate, blood lactate concentration, force and rate of force development (RFD) at the handle, stroke rate, duty factor, movement kinematics of upper and lower limbs, and muscle activity of lumbar spine muscles iliocostalis and erector spinae (IC and ESL) were measured at the beginning and at the end of a 40-min rowing exercise at ~60% of peak power output, in eleven competitive rowers. Force of lumbar extension decreased, and blood lactate increased following submaximal exercise on both ergometers. No changes in RFD, duty factor, and muscle activity of IC occurred in response to submaximal exercise. Rowing on DYN elicited higher heart rate and modified rowing kinematics (stroke rate, acceleration of the lower limbs) without changes in temporal or force application patterns compared to rowing on STAT at the same power output. Rowing on DYN was also associated with increased activity of the lumbar spine muscle ESL, which could originate from a greater range of motion, or from an increased lumbar spine muscle activity, at the same overall power.

scholarly journals The Effect of a Knee Support on the Biomechanical Response of the Low Back

2007 ◽  
Vol 23 (4) ◽  
pp. 275-281 ◽  
Author(s):  
Yu Shu ◽  
Zongliang Jiang ◽  
Xu Xu ◽  
Gary A. Mirka
Keyword(s):  
A Priori ◽  
Ground Level ◽  
Erector Spinae ◽  
Low Back ◽  
Support Device ◽  
Sudden Loading ◽  
Torso Angle ◽  
Flexion Relaxation ◽  
Trunk Extensor ◽  
Further Development

Stooping and squatting postures are seen in a number of industries (e.g., agriculture, construction) where workers must work near ground level for extended periods of time. The focus of the current research was to evaluate a knee support device designed to reduce the biomechanical loading of these postures. Ten participants performed a series of sudden loading tasks while in a semisquat posture under two conditions of knee support (no support and fully supported) and two conditions of torso flexion (45 and 60°). A weight was released into the hands of the participants who then came to steady state while maintaining the designated posture. As they performed this task, the EMG responses of the trunk extensors (multifidus and erector spinae) were collected, both during the “sudden loading” phase of the trial as well as the steady weight-holding phase of the trial. As expected, the effects of torso flexion angle showed significant decreases in the activation of the multifidus muscles with greater torso angle (indicating the initiation of the flexion–relaxation response). Interestingly, the results showed that the knee support device had no effect on the activation levels of the sampled muscles, indicating that the loss of the degree of freedom from the ankle joint during the knee support condition had no impact on trunk extensor muscle response. The a priori concern with regard to these supports was that they would tend to focus loading on the low back and therefore would not serve as a potential ergonomic solution for these stooping/semisquatting tasks. Because the results of this study did not support this concern, further development of such an intervention is underway.

A Comparison of Clinical Spinal Mobility Measures to Experimentally Derived Lumbar Spine Passive Stiffness

2020 ◽  
Vol 36 (6) ◽  
pp. 397-407
Author(s):  
Liana M. Tennant ◽  
Erika Nelson-Wong ◽  
Joshua Kuest ◽  
Gabriel Lawrence ◽  
Kristen Levesque ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Erector Spinae ◽  
Spinal Mobility ◽  
Low Back ◽  
Tissue Stiffness ◽  
Mechanical Stiffness ◽  
Intervertebral Motion ◽  
Clinical Assessments ◽  
Local Tissue ◽  
Spinal Stiffness

Spinal stiffness and mobility assessments vary between clinical and research settings, potentially hindering the understanding and treatment of low back pain. A total of 71 healthy participants were evaluated using 2 clinical assessments (posteroanterior spring and passive intervertebral motion) and 2 quantitative measures: lumped mechanical stiffness of the lumbar spine and local tissue stiffness (lumbar erector spinae and supraspinous ligament) measured via myotonometry. The authors hypothesized that clinical, mechanical, and local tissue measures would be correlated, that clinical tests would not alter mechanical stiffness, and that males would demonstrate greater lumbar stiffness than females. Clinical, lumped mechanical, and tissue stiffness were not correlated; however, gradings from the posteroanterior spring and passive intervertebral motion tests were positively correlated with each other. Clinical assessments had no effect on lumped mechanical stiffness. The males had greater lumped mechanical and lumbar erector spinae stiffness compared with the females. The lack of correlation between clinical, tissue, and lumped mechanical measures of spinal stiffness indicates that the use of the term “stiffness” by clinicians may require reevaluation; clinicians should be confident that they are not altering mechanical stiffness of the spine through segmental mobility assessments; and greater resting lumbar erector stiffness in males suggests that sex should be considered in the assessment and treatment of the low back.

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