THE IMPACT OF SEATBACK ANGLE ON ELECTROMYOGRAPHICAL ACTIVITY OF THE LOWER BACK AND QUADRICEPS MUSCLES DURING BILATERAL KNEE EXTENSION

AbstractStandard outcomes of traditional isokinetic testing do not detect differences between various muscle mechanical properties. This study i) explored a novel analysis throughout the range of motion based on statistical parametric mapping and ii) examined the impact of sex and discipline on hamstrings/quadriceps torque in elite alpine skiers. Twenty-eight national team skiers (14 females, 14 males; 14 technical, 14 speed) undertook an isokinetic evaluation of the knee flexors/extensors (range 30–90°, 0° representing full extension). There was no effect of sex (p=0.864, d=0.03) and discipline (p=0.360, d=0.17) on maximal hamstrings-to-quadriceps ratio and no effect of discipline on maximal torque (p>0.156, d≤0.25). Hamstrings torque and hamstrings-to-quadriceps ratio were lower in females than males toward knee extension only (p<0.05). Quadriceps torque was greater after 72° of knee flexion in technicians than downhill skiers (p<0.05). The current data showed that statistical parametric mapping analysis identified angle-specific differences that could not be evidenced when analyzing only maximal torques and reconstructed ratios. This may enhance screening methods to identify pathologic knee function or monitor rehabilitation programs, and inform sex- and discipline-specific training in alpine skiing.

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The Effects of Repetitive Drop Jumps on Impact Phase Joint Kinematics and Kinetics

Journal of Applied Biomechanics ◽

10.1123/jab.27.2.108 ◽

2011 ◽

Vol 27 (2) ◽

pp. 108-115 ◽

Cited By ~ 24

Author(s):

Joshua T. Weinhandl ◽

Jeremy D. Smith ◽

Eric L. Dugan

Keyword(s):

Energy Absorption ◽

Plantar Flexion ◽

Knee Extension ◽

Joint Kinematics ◽

Knee Extensors ◽

Initial Contact ◽

Drop Jumps ◽

Impact Phase ◽

The Impact ◽

Kinematics And Kinetics

The purpose of the study was to investigate the effects of fatigue on lower extremity joint kinematics, and kinetics during repetitive drop jumps. Twelve recreationally active males (n= 6) and females (n= 6) (nine used for analysis) performed repetitive drop jumps until they could no longer reach 80% of their initial drop jump height. Kinematic and kinetic variables were assessed during the impact phase (100 ms) of all jumps. Fatigued landings were performed with increased knee extension, and ankle plantar flexion at initial contact, as well as increased ankle range of motion during the impact phase. Fatigue also resulted in increased peak ankle power absorption and increased energy absorption at the ankle. This was accompanied by an approximately equal reduction in energy absorption at the knee. While the knee extensors were the muscle group primarily responsible for absorbing the impact, individuals compensated for increased knee extension when fatigued by an increased use of the ankle plantar flexors to help absorb the forces during impact. Thus, as fatigue set in and individuals landed with more extended lower extremities, they adopted a landing strategy that shifted a greater burden to the ankle for absorbing the kinetic energy of the impact.

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Listening to the body and talking to myself – the impact of chronic lower back pain: A qualitative study

International Journal of Nursing Studies ◽

10.1016/j.ijnurstu.2009.09.012 ◽

2010 ◽

Vol 47 (5) ◽

pp. 586-592 ◽

Cited By ~ 36

Author(s):

Marie Crowe ◽

Lisa Whitehead ◽

Mary Jo Gagan ◽

G. David Baxter ◽

Avin Pankhurst ◽

...

Keyword(s):

Back Pain ◽

Qualitative Study ◽

Lower Back Pain ◽

The Body ◽

Chronic Lower Back Pain ◽

Lower Back ◽

The Impact

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Survey of Musculoskeletal Injuries among Female Bharatanatyam Dancers in the Udupi District of India

Medical Problems of Performing Artists ◽

10.21091/mppa.2021.3022 ◽

2021 ◽

Vol 36 (3) ◽

pp. 199-206

Author(s):

Lavanya P Kumar ◽

Shruti J Shenoy

Keyword(s):

Medical Professional ◽

Musculoskeletal Injuries ◽

Limited Information ◽

Classical Dance ◽

Dance Training ◽

Lower Back ◽

Injury Occurrence ◽

Indian Classical Dance ◽

The Impact ◽

And Training

BACKGROUND: Bharatanatyam is an Indian classical dance form that is practiced globally. There is limited information about the prevalence of injuries in Bharatanatyam dancers. OBJECTIVES: To investigate the prevalence of musculoskeletal injuries and specifics of dance training in female Bharatanatyam dancers in the Udupi district of India. METHODS: We developed and tested a survey for Bharatanatyam dancers regarding injury history in the prior year, including location, time loss, cause, and need for medical help. We also obtained demographic and training information. RESULTS: 101 dancers completed the survey. 10.8% of dancers reported musculoskeletal injuries because of participation in dance. They sustained 0.65 injuries/1,000 hours of dancing. The most frequently injured areas were ankle (27.2%) and knee (27.2%) followed by lower back (13.6%) and hip (9%). Despite being injured, 36.4% of the dancers continued to dance. 54.5% of the injured dancers sought the help of a medical professional for their dance-related injuries. The most common surface for dance was concrete followed by other hard surfaces such as marble and tile. CONCLUSION: Female Bharatanatyam dancers are prone to injuries of the lower extremity and back. Most dancers in our study practice the Pandanalluru style on hard surfaces. There is a need to investigate the impact of training factors on the injury occurrence.

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Liver Fibrosis is Associated with a Decrease in Gait Speed in Older Men with Chronic Liver Disease: A Retrospective Cross-Sectional Study

10.21203/rs.3.rs-819599/v1 ◽

2021 ◽

Author(s):

Kenichi Fudeyasu ◽

Takuo Nomura ◽

Toshihiro Kawae ◽

Daisuke Iwaki ◽

Yuki Nakashima ◽

...

Keyword(s):

Liver Disease ◽

Liver Fibrosis ◽

Chronic Liver Disease ◽

Motor Function ◽

Gait Speed ◽

Older Patients ◽

Knee Extension ◽

Chronic Liver ◽

Cross Sectional ◽

The Impact

Abstract Background: Although it has already been reported that chronic liver disease (CLD) can induce sarcopenia, the impact of sarcopenia, especially on motor function, in older patients with CLD is still unclear. Therefore, we investigated the effects of liver fibrosis on motor function in these patients.Methods: In all, 117 older patients with CLD aged above 60 years (men, n=70; women, n=47) were included in this study. We examined the presence or absence of sarcopenia and checked motor functions such as muscle strength and walking speed. The results were compared between patients with FIB-4 index of >3.25, indicative of severe-degree liver fibrosis (SLF), and those with an index of <3.25, indicative of low-degree liver fibrosis (LLF). We also analyzed the factors related to the decrease in gait speed.Results: The decrease in gait speed (<1.0 m/s) was significantly higher (P = 0.027) and the knee extension force (KEF) was significantly lower (P = 0.010) in men with SLF than in those with LLF. In this study, liver fibrosis (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.56–0.90) and KEF (OR = 1.09, 95% CI = 1.02–1.16) were identified as factors associated with the decrease in gait speed.Conclusions: Older male patients with CLD have decreased motor function as the disease progresses. We found that the decrease in gait speed is related to liver fibrosis and KEF. It is necessary to focus on the motor function of older patients with CLD, especially the gait speed.

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Effectiveness of hamstring stretching using a pressure biofeedback unit for 4 weeks: A randomized controlled trial

Hong Kong Physiotherapy Journal ◽

10.1142/s1013702520500092 ◽

2020 ◽

Vol 40 (02) ◽

pp. 99-107

Author(s):

Jin-Oh Ahn ◽

Jong-Hyuck Weon ◽

Eun-Kyung Koh ◽

Do-Young Jung

Keyword(s):

Controlled Trial ◽

Intervention Group ◽

Knee Extension ◽

Control Group ◽

Post Intervention ◽

Lower Back ◽

Hamstring Muscles ◽

Before And After ◽

The Difference ◽

Pressure Biofeedback

Background: Stretching and length test of hamstring muscles have been performed commonly to manage lower back pain (LBP) in sports rehabilitation. Previous literatures addressed that stretching techniques and length test of hamstring muscles should be performed with the pelvic maintained in an anterior tilt position. However, there is no study to determine the effectiveness of pressure biofeedback unit (PBU) to maintain in anterior pelvic tilting (APT) on length test and stretching of hamstring muscles. Objective: To determine the effectiveness of hamstring muscles stretching using a PBU. Methods: Forty participants with shortness of hamstrings randomized into two groups. Participants performed the active knee extension (AKE) stretching without (control group) or with PBU (intervention group) for four weeks. AKE tests without and with PBU were administered three times before and after hamstrings stretching by each group. Results: The AKE test without PBU showed a significant main effect of time ([Formula: see text]) but not of group ([Formula: see text]) on the AKE angle. The AKE test with PBU showed a significant increase in the AKE angle in the post-intervention compared to the pre-intervention assessments in both groups ([Formula: see text]). The difference of AKE angle between the pre- and post-intervention results was significantly greater in the intervention group than in the control group ([Formula: see text]). Conclusion: We recommend the use of a PBU to maintain the pelvic anterior tilting position when performing the AKE test or AKE stretching.

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Effects of a Wearable Carriage Aid on Whole-Body Physiological Measures and Balance

Applied Sciences ◽

10.3390/app10228076 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8076

Author(s):

Saad A. Alabdulkarim ◽

Abdulsalam M. Farhan ◽

Mohamed Z. Ramadan

Keyword(s):

Heart Rate ◽

Oxygen Consumption ◽

Minute Ventilation ◽

Aid Effectiveness ◽

Whole Body ◽

Physiological Measures ◽

Future Studies ◽

Lower Back ◽

The Impact ◽

Load Mass

Carriage tasks are common and can lead to shoulder and lower back injuries. Wearable carriage aids have shown mixed effects on local physical demand measures. This study examined the impact of a wearable carriage aid on whole-body physiological measures (normalized oxygen consumption, minute ventilation, respiratory rate, and heart rate) to obtain a more comprehensive assessment regarding aid effectiveness. Additionally, this study investigated the effect of wearing the device on perceived balance. The potential moderating effect of carried load mass was considered. The examination was conducted while walking on a treadmill at a constant speed (2 km/h) for 5 min and was completed by 16 participants. Wearing the device reduced normalized oxygen consumption (~14%), minute ventilation (~7%), and heart rate (~3%), while substantially improving perceived balance (~61%). These effects were consistent across examined carried load levels. Although this study highlighted the potential for the developed aid, future studies are required for more diverse and realistic testing conditions.

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Impact of a Chest Support on Lower Back Muscles Activity During Forward Bending

Applied Bionics and Biomechanics ◽

10.1155/2010/737412 ◽

2010 ◽

Vol 7 (2) ◽

pp. 131-142 ◽

Cited By ~ 2

Author(s):

Arma&gcirc;an Albayrak ◽

Richard H. M. Goossens ◽

Chris J. Snijders ◽

Huib de Ridder ◽

Geert Kazemier

Keyword(s):

Surgical Procedures ◽

Muscle Activity ◽

Body Posture ◽

Back Muscle ◽

Leg Muscles ◽

Lower Back ◽

Forward Bending ◽

User Groups ◽

Supporting Force ◽

The Impact

The present study is based on previous research on the poor body posture of surgeons and their experienced discomfort during surgical procedures. Since surgeons have head-bent and back-bent posture during open surgical procedures, a chest support is a viable supporting principle. This support is meant to reduce lower back pain by minimising lower back muscle activity. The aim of this study is to investigate the impact of a chest support on lower back muscle activity during forward bending and to establish a possible relation between supporting force and the kind of balancing strategy a person adopts. Use of the chest support shows a significant reduction of muscle activity in the lower back and leg muscles. Within the participants three user groups are identified as “sceptical users”, “non-trusters” and “fully trusters”, each following a different balancing strategy. Since there are different kinds of users, the designed body support should offer the possibility for altering the posture and should not constrain the user to take a certain body posture.

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Musculoskeletal Complaints in Occupational Therapists Compared to the General Population: A Cross-Sectional Study in Germany

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17144916 ◽

2020 ◽

Vol 17 (14) ◽

pp. 4916

Author(s):

Ronny Zenker ◽

Maria Girbig ◽

Janice Hegewald ◽

Irina Gilewitsch ◽

Mandy Wagner ◽

...

Keyword(s):

Musculoskeletal Disorders ◽

Occupational Therapists ◽

Cross Sectional Study ◽

Physical Factors ◽

Musculoskeletal Complaints ◽

Sectional Study ◽

Cross Sectional ◽

Lower Back ◽

Increased Risk ◽

The Impact

Occupational therapists (OTs) are exposed to physical factors at work, which can lead to an increased risk of musculoskeletal disorders. Most studies examining musculoskeletal complaints in OT report that the neck, shoulders, and lower back are most often afflicted. The aim of the present study was to examine the impact of work as an OT (focusing on specific work tasks) on specific musculoskeletal complaints compared to the general working population. A cross-sectional study involving a self-administered standardized questionnaire was conducted from January until October 2015 in Germany. In OT and the comparison group, the highest 12-month prevalence of musculoskeletal disorders were observed for the lower back, the neck, and the shoulders. In contrast, elevated prevalence ratios (PR) were found for OT in the thumbs (PR = 2.7; 95% CI = 1.9–3.8), the wrists (PR = 1.4; 95% CI = 1.1–1.8), and the elbows (PR = 1.5; 95% CI = 1.0–2.2). OTs were particularly exposed to high exertion hand activity and several stressful postures at work. In conclusion, OTs seem to be at risk of developing work-related musculoskeletal complaints in the thumbs, wrists, and elbows. Preventive measures should help to reduce the exposures caused by highly repetitive and forceful hand activities.

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