scholarly journals Evaluation of Multi-axial Active Suspension to Reduce Whole Body Vibration Exposures and Associated Biomechanical Loading in Mining Heavy Equipment Vehicle Operators

2019 ◽  
Vol 63 (1) ◽  
pp. 1034-1039
Author(s):  
Kiana Kia ◽  
Pete Johnson ◽  
Stephanie Fitch ◽  
Jack Dennerlein ◽  
Jay Kim
Keyword(s):  
Muscle Activity ◽  
Active Suspension ◽  
Erector Spinae ◽  
Joint Torque ◽  
Whole Body ◽  
Neck Muscle ◽  
Low Back ◽  
Motion Platform ◽  
Passive Suspension ◽  
Biomechanical Loading

The purpose of this study was to evaluate the efficacy of multi-axial (lateral + vertical) active suspension in reducing multi-axial WBV exposures and related biomechanical loading in the neck and low back as compared to an industry standard single-axial (vertical) passive suspension seat. In a repeated-measures laboratory study with 13 subjects, while recreating field-measure vehicle vibration on a 6-degree-of-freedom motion platform, we measured WBV [weighted average vibration: A(8) and vibration dose values: VDV(8)], net joint torque in the low back (L5/S1) and neck, muscle activity in low back (erector spinae) and neck muscle (splenius capitis). The results showed that the multi-axial active suspension seat was more effective in reducing vertical (Z-axis) WBV [A(8) and VDV(8)] as compared to the single-axial passive suspension seats (p < 0.001), while little difference between two suspension seats were found in lateral (Y) axis. The peak low back moment with respect to the sagittal (Y) axis was significantly lower on the multi-axial active suspension seat compared to the single-axial passive suspension seat (p=0.01). Despite lack of statistical significance, the low back and neck muscle activity tended to be lower on the multi-axial active suspension compared to the single-axial passive suspension. These results indicate that the multi-axial suspension may have potential to reduce biomechanical loading in the low back.

Comparisons of Whole Body Vibration, Muscle Activity and Non-driving Task Performance between Different Seat Suspensions in an Autonomous Passenger Car Application

2018 ◽  
Vol 62 (1) ◽  
pp. 1848-1852
Author(s):  
Kiana Kia ◽  
Peter W Johnson ◽  
Jeong Ho Kim
Keyword(s):  
Task Performance ◽  
Muscle Activity ◽  
Whole Body Vibration ◽  
Active Suspension ◽  
Whole Body ◽  
Low Back ◽  
Motion Platform ◽  
Body Vibration ◽  
Pointing Task ◽  
Driving Task

This study compared whole body vibration (WBV), muscle activity and non-driving task performance between different seat suspension settings in a simulated autonomous passenger car environment. To simulate autonomous vehicle environment, field-measured vibration profiles were recreated on a large-scale 6-degree-of-freedom motion platform. In a repeated-measures laboratory experiment, we measured whole body vibration, muscle activity (neck, shoulder and low back), participants non-driving task performance while participants performed non-driving tasks (pointing task with a laptop trackpad, keyboard typing, web-browsing, and reading) on three different suspension seats mounted on the motion platform: vertical (z-axis) electromagnetic active suspension, multi-axial (lateral (y-axis) and vertical (z-axis)) electromagnetic active suspension, and no suspension (industry standard suspension-less seat for passenger cars). The average weighted vibration [A(8)] and vibration dose value [VDV(8)] showed that the seat measured vibration on both the vertical [A(8) = 0.29 m/s2 and VDV(8) = 10.70 m/s1.75] and multi-axial suspension seats [A(8) = 0.29 m/s2 and VDV(8) = 10.22m/s1.75] were lower than no-suspension seat vibration [A(8) = 0.36 m/s2 and VDV(8) = 12.84 m/s1.75]. Despite the significant differences in WBV between the different suspensions there were no significant differences across three different suspension seats in typing performance (typing speed and accuracy: p’s > 0.83), pointing task performance (movement time and accuracy: p’s > 0.87), web-browsing (number of questions and webpages read: p = 0.42), and reading (number of words read: p = 0.30). The muscle activity in low back (erector spinae) and shoulder (trapezius) muscles also did not show any significant differences (p’s > 0.22). These laboratory study findings indicated that despite the significant reduction in WBV, neither vertical nor multi-axial active suspension seats improve non-driving task performance as compared to the no-suspension seat.

scholarly journals Effects of Whole Body Vibration exercise on Lumbar-Abdominal Muscles Activation for patients with chronic low back pain

2020 ◽  
Author(s):  
yulin dong ◽  
huifang wang ◽  
Yan Zhu ◽  
Binlin Chen ◽  
Yili Zheng ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Chronic Low Back Pain ◽  
Muscle Activity ◽  
Whole Body Vibration ◽  
Abdominal Muscle ◽  
Erector Spinae ◽  
Whole Body ◽  
Low Back ◽  
Body Vibration

Abstract BackgroundWhole body vibration (WBV) training as an intervention method can cure chronic low back pain (CLBP). Different WBV parameters exert different effects on lumbar-abdominal muscle performance. Currently, there is a lack of study researched the influence of WBV training on patients with CLBP by lumbar–abdominal muscle activity. Therefore, this study aimed to investigate how WBV and exercise and their interactions influence lumbar-abdominal muscle activity in patients with CLBP.Methodsa group of ambulatory patients with chronic low back pain. Muscle activities of the multifidus, erector spinae, abdominal oblique externus muscle and the rectus abdominis muscle were measured by surface electromyography, whereas participants performed 4 different exercises during three whole body vibration conditions and a no-vibration condition in a single experimental session.ResultsCompared with the same exercises without whole body vibration, muscle activity increased when whole body vibration was added to the exercises. The frequency and exercise presented significant effects on the root mean square of multifidus, whereas exercise and frequency also resulted in significant interaction effects.ConclusionAdding whole body vibration to exercise could increase muscle activation of lumbar–abdominal muscle in patients with CLBP. The optimum frequency for lumbar–abdominal muscles is 15 Hz. The best exercises include plank for multifidus and erector spinae, V crunch for rectus abdominis and single bridge for abdominal oblique externus.Trial registration:ChiCTR-TRC-13003708. Registered 19 October 2013, http://www.chictr.org.cn/showproj.aspx?proj=5852

The Comparisons of Whole Body Vibration Exposures and Supporting Musculature Loading between Single- and Multi-axial Suspension Seats during Agricultural Tractor Operation

2016 ◽  
Vol 60 (1) ◽  
pp. 923-927 ◽  
Author(s):  
Jeong Ho Kim ◽  
Jack T Dennerlein ◽  
Peter W Johnson
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Whole Body Vibration ◽  
Erector Spinae ◽  
Whole Body ◽  
Low Back ◽  
Body Vibration ◽  
Repeated Measures Design ◽  
Industry Standard ◽  
Agricultural Tractor

Due to rough terrain, agricultural tractor drivers are likely exposed to a high level of whole body vibration, especially impulsive shocks. These WBV exposures are often predominant in the fore-aft (x) or lateral (y) axis. However, the current industry standard seats are designed to reduce mainly vertical (z) axis WBV exposures, and therefore, may be less effective in reducing tractor drivers’ exposure to WBV. Therefore, in a repeated-measures design with 11 subjects, this study evaluated efficacy of a multi-axial (vertical + lateral) suspension seat in reducing WBV exposure and low back (erector spinae) muscle activity relative to an industry standard single-axial suspension seat. The results showed that while there was no difference in fore-aft (x) and vertical (z) axis WBV exposures between the seats, the multi-axial suspension seat had lower A(8) lateral (y) WBV exposures [median (interquartile range): 0.7 (0.41, 0.83) m/s2] and VDV(8) [13.5 (7.4, 16.4) m/s1.75] WBV exposures than the single-axial suspension seats [ A(8): 0.81 (0.48 0.93) m/s2; VDV(8): 13.5 (8.7, 18.5) m/s1.75] (p = 0.02 and 0.04, respectively). Low back muscle activity was also lower on the multi-axial suspension seats, however this difference was not significantly significant. These results indicate that mu the multi-axial suspension may have potential to reduce the WBV exposures and muscular loading on low back among agricultural vehicle operators.

scholarly journals Alteration in HDEMG Spatial Parameters of Trunk Muscle Due to Handle Design during Pushing

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6646
Author(s):  
Jacqueline Toner ◽  
Jeremy Rickards ◽  
Kenneth Seaman ◽  
Usha Kuruganti
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Trunk Muscle ◽  
Erector Spinae ◽  
Low Back ◽  
Horizontal Orientation ◽  
Low Back Injuries ◽  
Spatial Parameters ◽  
Left And Right ◽  
Pushing And Pulling

Previous research identifies that pushing and pulling is responsible for approximately 9–18% of all low back injuries. Additionally, the handle design of a cart being pushed can dramatically alter a worker’s capacity to push (≅9.5%). Surprisingly little research has examined muscle activation of the low back and its role in muscle function. Therefore, the purpose of this study was to examine the effects of handle design combination of pushing a platform truck cart on trunk muscle activity. Twenty participants (10 males and 10 females, mean age = 24.3 ± 4.3 years) pushed 475 lbs using six different handle combinations involving handle orientation (vertical/horizontal/semi-pronated) and handle height (hip/shoulder). Multichannel high-density EMG (HDsEMG) was recorded for left and right rectus abdominis, erector spinae, and external obliques. Pushing at hip height with a horizontal handle orientation design (HH) resulted in significantly less (p < 0.05) muscle activity compared to the majority of other handle designs, as well as a significantly higher entropy than the shoulder handle height involving either the semi-pronated (p = 0.023) or vertical handle orientation (p = 0.028). The current research suggests that the combination of a hip height and horizontal orientation handle design may require increased muscle demand of the trunk and alter the overall muscle heterogeneity and pattern of the muscle activity.

Whole body muscle activity during weightlifting exercise evaluated by positron emission tomography

2021 ◽  
Author(s):  
Rikuto Yoshimizu ◽  
Junsuke Nakase ◽  
Takafumi Mochizuki ◽  
Yasushi Takata ◽  
Kengo Shimozaki ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Muscle Activity ◽  
Erector Spinae ◽  
Triceps Surae ◽  
Emission Tomography ◽  
Whole Body ◽  
Computed Tomography Images ◽  
Positron Emission ◽  
The Right ◽  
Fdg Accumulation

Abstract BackgroundThis study investigated the whole-body skeletal muscle activity pattern of hang power clean (HPC), a major weight training exercise, using positron emission tomography (PET).MethodTwelve college weightlifting athletes performed three sets of HPC 20 times with a barbell set to 40 kg both before and after an intravenous injection of 37 MBq 18F-fluorodeoxyglucose (FDG). PET-computed tomography images were obtained 50 min after FDG injection. Regions of interest were defined within 71 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume, and FDG accumulation was compared to the control group. The Mann–Whitney U-test was used to evaluate the differences in the mean SUV between groups. The difference between SUVs of the right and left muscles was evaluated by a paired t-test. A P-value < 0.05 was considered statistically significant.ResultsFDG accumulation within the vastus lateralis, vastus intermedius, and vastus medialis was higher than that of the rectus femoris. FDG accumulation within the triceps surae muscle was significantly higher only in the soleus. In the trunk and hip muscles, FDG accumulation of only the erector spinae was significantly increased. In all skeletal muscles, there was no difference between SUVs of the right and left muscles.ConclusionsThe monoarticular muscles in the lower limbs were active in HPC. In contrast, deep muscles in the trunk and hip were not active during HPC. HPC is not suitable for core training and needs to be supplemented with other training.

scholarly journals Physiological and Muscular Stress Associated with Multi-axial Whole-Body Vibration Exposure in Mining Heavy Equipment Vehicle Environment

2019 ◽  
Vol 63 (1) ◽  
pp. 1040-1045
Author(s):  
Kiana Kia ◽  
Stephanie Fitch ◽  
Sean Newsom ◽  
Jay Kim
Keyword(s):  
Creatine Kinase ◽  
Muscle Damage ◽  
Muscle Activity ◽  
Physiological Stress ◽  
Whole Body Vibration ◽  
Vertical Axis ◽  
Whole Body ◽  
Vibration Exposure ◽  
Low Back ◽  
Mining Vehicles

Whole-body vibration (WBV) is known to be a leading factor for developing musculoskeletal disorders (MSDs). As mining vehicle operators are exposed to frequent transient shocks and substantial non-vertical WBV exposures, they may be at a greater risk than on-road vehicle operators. However, the impact of such exposures is not well understood. Therefore, this study aimed to evaluate how the exposure to WBV affected physiological stress and whether mining vehicles’ vibration with substantial non-vertical WBV components would further increase the level of physiological stress as compared to on-road vehicle vibration (vertical-axis dominant vibration). In a repeated-measures laboratory study, a 6-degree-of-freedom motion platform was used to recreate three different types of field-collected vibration profiles: vertical-axis dominant vibration measured from on-road long-haul trucks (VA), multi-axial vibration measured from mining vehicles (MA), and no vibration (control condition: CC). Subjects were exposed to each vibration condition for 2-hour sessions over three different experimental days. Blood samples were collected before and after each exposure session in order to measure biological markers for inflammation (tumor necrosis factor-α: TNFα), muscle damage (creatine kinase), and physiological stress (cortisol). During the 2-hour WBV exposures, muscle activity in the neck and low back muscles was measured using electromyography. The results showed that there were statistically significant differences in TNFα (inflammatory response) levels between vibration exposure (VA and MA) and the control condition (no vibration) (p = 0.01); however, these differences are not considered as clinically significant changes. No significant changes were found in muscle damage (creatine kinase) and physiological stress (cortisol). The vibration exposure conditions (VA and MA) showed higher low back muscle activity; however, these differences did not reach statistical significance (p’s > 0.08). Neck muscle activity did not differ among exposure conditions. The lack of effect in these results may support previous findings that MSDs develop from prolonged exposure to WBV and not from acute exposure to physical risk factors.

Evaluation of Different Patient Transfer Devices in Reducing Biomechanical Exposures among Professional Caregivers

2018 ◽  
Vol 62 (1) ◽  
pp. 933-937
Author(s):  
Jaejin Hwang ◽  
Veera Aneesh Kuppam ◽  
Subhramanya Suryanarayana Raju Chodraju ◽  
Jie Chen ◽  
Jeong Ho Kim
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Patient Transfer ◽  
Erector Spinae ◽  
Low Back ◽  
Pull Force ◽  
Engineering Controls ◽  
Full Force ◽  
Transfer Tasks

This study systematically investigated the efficacy of commercially-available patient transfer devices (a slide sheet, slide board, air-assisted device, and conventional draw sheet) in reducing biomechanical exposures during standardized lateral patient transfer tasks. A repeated-measures laboratory study with 10 experienced caregivers (9 females and 1 male) was conducted to measure the muscle activity in the upper extremity (flexor digitorum superficialis, extensor digitorum communis, biceps, triceps, and trapezius) and low back (erector spinae), and hand pull force and during standardized lateral patient transfer tasks with four different commercially-available transfer devices. The results showed that there were significant differences between the transfer devices in muscle activity (p’s < 0.01) and hand pull force (p < 0.01). The air-assisted device showed the largest reduction of muscle activities and hand pull force. The slide board also showed lower muscle activities and hand full force as compared to the slide sheet and conventional draw sheet; however, limited differences in muscle activity and hand pull force were found between the slide sheet and conventional draw sheet. These findings indicate that the air-assisted device and slide board may be effective engineering controls to reduce the biomechanical exposures and associated injury risks in the upper extremity and low back among caregivers.

Electromyographic Activity of Trunk Muscles During Flexion-Distraction Treatment of Low Back Patients

1999 ◽  
Author(s):  
Maruti R. Gudavalli ◽  
Jerrilyn A. Backman ◽  
Steven J. Kirstukas ◽  
Anant V. Kadiyala ◽  
Avinash G. Patwardhan ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Low Back ◽  
Mean Values ◽  
Flexion Extension ◽  
Left And Right ◽  
The Mean

Abstract The objective of this study was to determine the electromyographic (EMG) activity of the superficial muscles during the treatment of low back patients during a conservative procedure known as the Cox flexion-distraction procedure. A total of 33 low back pain patients were recruited for this study from chiropractic and allopathic orthopedic clinics. EMG signals were collected while the patient was in a prone relaxed position, during the treatment using the flexion-distraction procedure, and during maximum voluntary exertions in the three planes (flexion, extension, left and right lateral bending, and left and right twisting). The mean values of the Root Mean Square (RMS) values of EMG ratios during treatment versus resting indicate that the muscles are active during the treatment. This activity is more than the activity at rest. However the mean values of the RMS EMG ratios (during treatment versus maximum voluntary contraction) are small indicating that the muscle activity during treatment may not influence the treatment loads. The left and right muscles in all muscle groups were similarly active. During the treatment, erector spinae muscles were the most active, followed by the external oblique, and the rectus abdominus muscles. The results from this study provide quantitative data for the muscle activity during the flexion-distraction treatment. This information can be incorporated into computer models to estimate the loads generated during the flexion-distraction treatment due to the muscle activity compared to the loads generated by the chiropractic physician.

scholarly journals Association between lumbopelvic motion and muscle activation in patients with non-specific low back pain during forward bending task: A cross-sectional study

2019 ◽  
Vol 40 (01) ◽  
pp. 29-37
Author(s):  
Peemongkon Wattananon ◽  
Komsak Sinsurin ◽  
Sirikarn Somprasong
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Erector Spinae ◽  
Low Back ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Forward Bending ◽  
Lumbar Motion

Background: Evidence suggests patients with non-specific low back pain (NSLBP) have altered lumbar and pelvic movement patterns. These changes could be associated with altered patterns of muscle activation. Objective: The study aimed to determine: (1) differences in the relative contributions and velocity of lumbar and pelvic movements between people with and without NSLBP, (2) the differences in lumbopelvic muscle activation patterns between people with and without NSLBP, and (3) the association between lumbar and pelvic movements and lumbopelvic muscle activation patterns. Methods: Subjects (8 healthy individuals and 8 patients with NSLBP) performed 2 sets of 3 repetitions of active forward bending, while motion and muscle activity data were collected simultaneously. Data derived were lumbar and pelvic ranges of motion and velocity, and ipsilateral and contralateral lumbopelvic muscle activities (internal oblique[Formula: see text]transverse abdominis (IO[Formula: see text]TA), lumbar multifidus (LM), erector spinae (ES) and gluteus maximus (GM) muscles). Results: Lumbar and pelvic motions showed trends, but exceeded 95% confidence minimal detectable difference (MDD[Formula: see text]), for greater pelvic motion [Formula: see text], less lumbar motion [Formula: see text] among patients with NSLBP. Significantly less activity was observed in the GM muscles bilaterally [Formula: see text] in the NSLBP group. A significant association [Formula: see text], [Formula: see text] was found between ipsilateral ES muscle activity and lumbar motion, while moderate, but statistically non-significant associations, were found between GM muscle activity bilaterally and lumbar velocity [Formula: see text]ipsilateral: [Formula: see text], [Formula: see text]; contralateral: [Formula: see text], [Formula: see text] in the NSLBP group. Conclusion: Findings indicated patients had greater pelvic contribution, but less lumbar contribution which was associated with less activation of the GM bilaterally.

scholarly journals Guidelines for Working Heights of the Lower-Limb Exoskeleton (CEX) Based on Ergonomic Evaluations

2021 ◽  
Vol 18 (10) ◽  
pp. 5199
Author(s):  
Yong-Ku Kong ◽  
Chae-Won Park ◽  
Min-Uk Cho ◽  
Seoung-Yeon Kim ◽  
Min-Jung Kim ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Biceps Brachii ◽  
Erector Spinae ◽  
Whole Body ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Lower Limb Exoskeleton ◽  
Upper Trapezius ◽  
Subjective Discomfort

The aim of this study was to evaluate the muscle activities and subjective discomfort according to the heights of tasks and the lower-limb exoskeleton CEX (Chairless EXoskeleton), which is a chair-type passive exoskeleton. Twenty healthy subjects (thirteen males and seven females) participated in this experiment. The independent variables were wearing of the exoskeleton (w/ CEX, w/o CEX), working height (6 levels: 40, 60, 80, 100, 120, and 140 cm), and muscle type (8 levels: upper trapezius (UT), erector spinae (ES), middle deltoid (MD), triceps brachii (TB), biceps brachii (BB), biceps femoris (BF), rectus femoris (RF), and tibialis anterior (TA)). The dependent variables were EMG activity (% MVC) and subjective discomfort rating. When wearing the CEX, the UT, ES, RF, and TA showed lower muscle activities at low working heights (40–80 cm) than not wearing the CEX, whereas those muscles showed higher muscle activities at high working heights (100–140 cm). Use of the CEX had a positive effect on subjective discomfort rating at lower working heights. Generally, lower discomfort was reported at working heights below 100 cm when using the CEX. At working heights of 100–140 cm, the muscle activity when wearing the CEX tended to be greater than when not wearing it. Thus, considering the results of this study, the use of the lower-limb exoskeleton (CEX) at a working height of 40–100 cm might reduce the muscle activity and discomfort of whole body and decrease the risk of related disorders.

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