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.

Effect of Absolute and Relative Loading on Muscle Activity During Stable and Unstable Squatting

2010 ◽  
Vol 5 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Jeffrey M. McBride ◽  
Tony R. Larkin ◽  
Andrea M. Dayne ◽  
Tracie L. Haines ◽  
Tyler J. Kirby
Keyword(s):  
Body Mass ◽  
Muscle Activity ◽  
Vastus Lateralis ◽  
Force Plate ◽  
Rest Period ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Repetition Maximum ◽  
Maximum Test ◽  
Significant Difference

Purpose:The purpose of this investigation was to determine the effect of stable and unstable conditions on one repetition maximum strength and muscle activity during dynamic squatting using absolute and relative loading.Methods:Ten recreationally weight-trained males participated in this study (age = 24.1 ± 2.0 y, height = 178.0 ± 5.6 cm, body mass = 83.7 ± 13.4 kg, 1RM/body mass = 1.53 ± 0.31), which involved two laboratory sessions separated by 1 wk. Linear position transducers were used to track bar displacement while subjects stood on a force plate for all trials. Vastus lateralis (VL), biceps femoris (BF) and erector spinae (L1) muscle activity (average integrated EMG [IEMG]) was also recorded during all trials. During the frst session subjects complete a one repetition maximum test in a stable dynamic squat (S1RM = 128.0 ± 31.4 kg) and an unstable dynamic squat (U1RM = 83.8 ± 17.3 kg) in a randomized order with a 30-min rest period between conditions. The second session consisted of the performance of three trials each for 12 different conditions (unstable and stable squats using three different absolute loads [six conditions] and unstable and stable squats using three different relative loads [six conditions]).Results:Results revealed a statistically significant difference between S1RM and U1RM values (P < .05). The stable trials resulted in the same or a significantly higher value for VL, BF and L1 muscle activity in comparison with the unstable trials for all twelve conditions.Conclusions:Unstable squatting is of equal or less (depending on the loading condition) benefit to improving or maximizing muscle activity during resistance exercise.

Muscle activities of lower extremity and erector spinae muscles according to ankle joint position during squat exercise

2021 ◽  
pp. 1-6
Author(s):  
Ha-Rim Sung ◽  
Se-Jung Oh ◽  
Jun-Nam Ryu ◽  
Yong-Jun Cha
Keyword(s):  
Lower Extremity ◽  
Ankle Joint ◽  
Muscle Activity ◽  
Vastus Lateralis ◽  
Plantar Flexion ◽  
Erector Spinae ◽  
Neutral Position ◽  
Vastus Medialis ◽  
Joint Position ◽  
Squat Exercise

OBJECTIVE: The purpose of this study was to investigate the most effective ankle joint position for squat exercise by comparing muscle activities of lower extremity and erector spinae muscles in different ankle joint positions. METHODS: Thirty-seven normal healthy adults in their 20s participated in this study. Muscle activities of dominant vastus medialis oblique, vastus lateralis, biceps femoris, and erect spinae were measured in three ankle joint positions; dorsiflexion, neutral, and plantar flexion. RESULTS: Muscle activities of the vastus medialis oblique, vastus lateralis, and erector spinae muscles were statistically different in the three ankle joint positions during squat exercise (p< 0.05). Vastus medialis oblique muscles showed higher muscle activity in ankle plantar flexion than in the dorsiflexion or neutral positions (plantar flexion > neutral position, +3.3% of maximal voluntary isometric contraction (MVIC); plantar flexion > dorsiflexion, +12.2% of MVIC, respectively). Vastus lateralis muscles showed 7.1% of MVIC greater muscle activity in the neutral position than in dorsiflexion, and erector spinae muscles showed higher muscle activity in dorsiflexion than in plantar flexion or in the neutral position (dorsiflexion > neutral position, +4.3% of MVIC; dorsiflexion > plantar flexion, +7.1% of MVIC, respectively). CONCLUSION: In squat exercises designed to strengthen the vastus medialis oblique, ankle joint plantar flexion is probably the most effective ankle training position, and the dorsiflexion position might be the most effective exercise for strengthening the erector spinae muscle.

scholarly journals The effect of a vastus lateralis tape on muscle activity during stair climbing

2009 ◽  
Vol 14 (3) ◽  
pp. 330-337 ◽  
Author(s):  
U. McCarthy Persson ◽  
H.F. Fleming ◽  
B. Caulfield
Keyword(s):  
Muscle Activity ◽  
Vastus Lateralis ◽  
Stair Climbing

Influence of Shock Waves and Muscle Activity at Initial Contact on Walk–Run Transition Evaluated by Two Models

2009 ◽  
Vol 25 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Kin Shung ◽  
Carlos G. de Oliveira ◽  
Jurandir Nadal
Keyword(s):  
Shock Waves ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Vastus Lateralis ◽  
Lumbar Vertebra ◽  
Erector Spinae ◽  
Human Gait ◽  
Initial Contact ◽  
Transition Speed ◽  
Biological Phenomena

The walk–run transition (WRT) is a well-described phenomenon without any known cause; however, mechanical variables related to human gait have been associated with the WRT. This study tested the hypothesis that shock waves in the tibia and 3rd lumbar vertebra in addition to activity of tibialis anterior, vastus lateralis, and erector spinae muscles could be responsible for the WRT. Thirty subjects walked and ran on a treadmill at 80%, 90%, 100%, 110%, and 120% of preferred transition speed. Shock waves were measured with skin-mounted accelerometers and muscle activity by surface electromyography. The influence on the WRT was analyzed with two models. The shock waves and muscle activity tended to a significant increase (p< .05) for both walking and running with increased speed. The only factor that appeared to be involved in the WRT mechanism was the activity of the tibialis anterior; however, this was only confirmed by one of the two models. The use of different models to analyze the same data for the WRT triggers may give different results; thus, a standard model is required to investigate the influence of given factors on biological phenomena.

Trunk Flexion and Musculoskeletal Stress during Light Assembly Work

2004 ◽  
Vol 20 (3) ◽  
pp. 230-242 ◽  
Author(s):  
Victor Paquet ◽  
Ranjit Nirmale
Keyword(s):  
Muscle Activity ◽  
Recovery Time ◽  
Interactive Effect ◽  
Recovery Period ◽  
Erector Spinae ◽  
Muscular Fatigue ◽  
Low Back ◽  
Trunk Flexion ◽  
Study Participants ◽  
Assembly Tasks

Mild trunk flexion held during working tasks throughout the day is considered a risk factor for low back pain. Exactly how the duration of these postures impacts the low back musculature during work tasks is not well understood. The objective of this study was to evaluate the effects of the temporal variation of mild trunk flexion and erect standing postures on low back discomfort and muscular fatigue, defined as a decrease in torso extension strength, during a realistic light assembly task. Study participants performed light assembly tasks for 20 minutes while in mild trunk flexion for periods of either 30 or 60 seconds, followed by recovery periods in which they stood erect, for periods of either 15, 30, 60, or 120 sec. Localized muscle discomfort, decreases in torso extension strength, and muscle activity of erector spinae were recorded. Duration of recovery period had a statistically significant effect on localized muscle discomfort of the lower back, upper back, and shoulders. Duration of trunk flexion and recovery time had an interactive effect on decreases in torso extension strength, for which strength decreased with decreasing recovery time and was more pronounced for trunk flexion periods of 60 sec rather than 30 sec. The mean RMS erector spinae muscle activity during mild trunk flexion was approximately 25% of the measured maximum voluntary RMS muscle activity across all conditions. The results suggest that it is the temporal pattern of muscular trunk flexion, and not the total time spent in trunk flexion, that affects localized discomfort and muscular fatigue of the low back.

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 Piezo-resistive MC Sensor is a Fast and Accurate Sensor for the Measurement of Mechanical Muscle Activity

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2108 ◽  
Author(s):  
Andrej Meglič ◽  
Mojca Uršič ◽  
Aleš Škorjanc ◽  
Srđan Đorđević ◽  
Gregor Belušič
Keyword(s):  
Muscle Activity ◽  
Skeletal Muscles ◽  
Time Course ◽  
Vastus Lateralis ◽  
Initial Pressure ◽  
Rectus Femoris ◽  
Signal Amplitude ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Vastus Medialis

A piezo-resistive muscle contraction (MC) sensor was used to assess the contractile properties of seven human skeletal muscles (vastus medialis, rectus femoris, vastus lateralis, gastrocnemius medialis, biceps femoris, erector spinae) during electrically stimulated isometric contraction. The sensor was affixed to the skin directly above the muscle centre. The length of the adjustable sensor tip (3, 4.5 and 6 mm) determined the depth of the tip in the tissue and thus the initial pressure on the skin, fatty and muscle tissue. The depth of the tip increased the signal amplitude and slightly sped up the time course of the signal by shortening the delay time. The MC sensor readings were compared to tensiomyographic (TMG) measurements. The signals obtained by MC only partially matched the TMG measurements, largely due to the faster response time of the MC sensor.

scholarly journals Optimizing athlete assessment of maximal force and rate of development: A comparison of the isometric squat and mid-thigh pull

2020 ◽  
Author(s):  
Joao Renato Silva ◽  
Vasileios Sideris ◽  
Bryna C.R. Chrismas ◽  
Paul J. Read
Keyword(s):  
Muscle Activity ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Biceps Femoris ◽  
Peak Force ◽  
Erector Spinae ◽  
Vastus Medialis ◽  
Rate Of Development ◽  
Hamstring Muscles ◽  
Force Time

ABSTRACTThis study compared force-time characteristics and muscle activity between the isometric squat (ISQ) and mid-thigh pull (IMTP) in both bilateral (ISQBI and IMTPBI) and unilateral (ISQUNI and IMTPUNI) stance. Peak force (PF), rate-of-force (RFD) (e.g. 0-300ms) and EMG of the multifidus, erector spinae (ES), gluteus maximus (GM), biceps femoris (BF), semitendinosus (ST), vastus medialis (VM), vastus lateralis (VL) and soleus were recorded in ten recreationally trained males. PF was significantly greater during the ISQBI vs. IMTPBI (p=0.016, ES=1.08) but not in the unilateral test mode although effects remained moderate (ES=0.62). A trend indicated heightened RFD300ms (p = 0.083; ES=0.81) during the IMTPBI vs. the ISQBI, but these effects were smaller in the unilateral test (ES = 0.51). Greater (p<0.0001) EMG for VL (ES=1.00-1.13) and VM were recorded during the ISQ compared to IMTP modes in both modes (ES = 0.97 – 1.18). Greater BF EMG (p = 0.030, ES = 0.31) was shown in IMTPBI vs. ISQBI and these effects were stronger in the unilateral modes (p = < 0.05; ES = 0.81 – 0.83). Significantly greater ST activation was shown in both IMTPUNI (p < 0.05; ES = 0.69-0.76) and IMTPBI (p < 0.001; ES = 1.08). These findings indicate that ISQ results in elevated PF, whereas, RFD is heightened during the IMTP and these differences are more pronounced in bilateral modes. Greater activation of the quadriceps and hamstring muscles are expected in ISQ and IMPT respectively.

Comparison among low intensity bridge exercises using suspension devices based on muscle activity and subjective difficulty

2021 ◽  
pp. 1-6
Author(s):  
Sang-Yeol Lee ◽  
Se-Yeon Park
Keyword(s):  
Inclination Angle ◽  
Muscle Activity ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Internal Oblique Muscle ◽  
Low Intensity ◽  
Erector Spinae Muscle ◽  
Internal Oblique

BACKGROUND: Recent clinical studies have revealed the advantages of using suspension devices. Although the supine, lateral, and forward leaning bridge exercises are low-intensity exercises with suspension devices, there is a lack of studies directly comparing exercise progression by measuring muscular activity and subjective difficulty. OBJECTIVE: To identify how the variations in the bridge exercise affects trunk muscle activity, the present study investigated changes in neuromuscular activation during low-intensity bridge exercises. We furthermore explored whether the height of the suspension point affects muscle activation and subjective difficulty. METHODS: Nineteen asymptomatic male participants were included. Three bridge exercise positions, supine bridge (SB), lateral bridge (LB), forward leaning (FL), and two exercise angles (15 and 30 degrees) were administered, thereby comparing six bridge exercise conditions with suspension devices. Surface electromyography and subjective difficulty data were collected. RESULTS: The rectus abdominis activity was significantly higher with the LB and FL exercises compared with the SB exercise (p< 0.05). The erector spinae muscle activity was significantly higher with the SB and LB exercises, compared with the FL exercise (p< 0.05). The LB exercise significantly increased the internal oblique muscle activity, compared with other exercise variations (p< 0.05). The inclination angle of the exercise only affected the internal oblique muscle and subjective difficulty, which were significantly higher at 30 degrees compared with 15 degrees (p< 0.05). CONCLUSIONS: Relatively higher inclination angle was not effective in overall activation of the trunk muscles; however, different bridge-type exercises could selectively activate the trunk muscles. The LB and SB exercises could be good options for stimulating the internal oblique abdominis, and the erector spinae muscle, while the FL exercise could minimize the erector spinae activity and activate the abdominal muscles.

Analysis of Muscle Activity Using Surface Electromyography for Muscle Performance in Manual Lifting Task

2014 ◽  
Vol 564 ◽  
pp. 644-649 ◽  
Author(s):  
Halim Isa ◽  
Rawaida ◽  
Seri Rahayu Kamat ◽  
A. Rohana ◽  
Adi Saptari ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Surface Electromyography ◽  
Biceps Brachii ◽  
Twist Angle ◽  
Erector Spinae ◽  
Manual Lifting ◽  
Experienced Fatigue ◽  
Left And Right ◽  
Lifting Task ◽  
Load Mass

In industries, manual lifting is commonly practiced even though mechanized material handling equipment are provided. Manual lifting is used to transport or move products and goods to a desired place.Improper lifting techniquescontribute to muscle fatigue and low back pain that can lead to work efficiency and low productivity.The objective of this study were to analyze muscle activity in the left and right Erector Spinae, and left and right Biceps Brachii of five female subjects while performing manual lifting taskwithdifferent load mass, lifting height and twist angle.The muscle activitywere measured and analyzed using surface electromyography (sEMG).This study found that the right Biceps Brachii, right and left Erector Spinae experienced fatigue while performingasymmetric lifting (twist angle = 90°) at lifting height of 75 cm and 140 cm with load mass of 5 kg and 10 kg. Meanwhile, the left Biceps Brachii experienced fatigue when the lifting task was set at lifting height of 75 cm, load mass of 5 kg and twist angle of 90°.The load mass and lifting height has a significant influence to Mean Power Frequency (MPF) for left Biceps Brachii, left and right Erector Spinae. This study concluded that reducing the load mass can increase the muscles performance which can extend the transition-to-fatigue stage in the left and right Biceps Brachii and Erector Spinae.

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