Breaking News
March 22, 2019 - Servier collaborates with Harvard researchers to fight metabolic diseases
March 22, 2019 - National Eating Disorders Association
March 22, 2019 - Pumping up red blood cell production
March 22, 2019 - Excessive phosphate fertilizer may hurt plants by altering microbial composition in soil
March 22, 2019 - Medical marijuana laws could be improving older Americans’ health, study suggests
March 22, 2019 - Study indicates the benefits of stopping aspirin in heart attack patients
March 22, 2019 - Deep brain stimulation offers significant relief for patients with treatment-resistant depression
March 22, 2019 - Mental health problems in young adults on the rise
March 22, 2019 - Innovative membrane offers a viable solution for periodontitis
March 22, 2019 - The FDA Grants Rare Pediatric Disease Designation to Odiparcil for the Treatment of MPS VI
March 22, 2019 - insulin therapy: MedlinePlus Medical Encyclopedia
March 22, 2019 - Guidelines on the use of genetic testing in psychiatry
March 22, 2019 - Aspiring Doctors Seek Advanced Training In Addiction Medicine
March 22, 2019 - A change in focus could enable the development of new treatments for Alzheimer’s disease
March 22, 2019 - A new way to visualize the immune cell “landscape” of bowel cancer tumors
March 22, 2019 - Understanding maintenance of quiescent stem cells in chronic myelogenous leukemia
March 22, 2019 - Ludwig scientists to share advances in cancer research at AACR Annual Meeting 2019
March 22, 2019 - Less invasive valve replacement can be safe and effective alternative for healthier patients
March 22, 2019 - Aphasia research reveals new, complex interactions between thought and language
March 22, 2019 - Artificial neural networks can predict how different areas in the brain respond to words
March 22, 2019 - Age-related changes to gut microbiome have adverse impact on vascular health, study shows
March 22, 2019 - Isolated seniors chat online to prevent cognitive decline
March 22, 2019 - Naltrexone implant more effective in reducing relapses in HIV patients with opioid addiction
March 22, 2019 - The Brain Institute wins $7.04 million grant to investigate ‘neurophilosphy of free will’
March 22, 2019 - Karyopharm Announces FDA Extension of Review Period for Selinexor New Drug Application
March 22, 2019 - Eruptive xanthomatosis
March 22, 2019 - Cause of vascular disease in kidney failure reversed in animal model
March 22, 2019 - Researchers discover possible new therapeutic strategy for pancreatic cancer
March 22, 2019 - Ebola spreads to second largest city in DRC
March 22, 2019 - Perivascular spaces contribute to worse cognitive health in older adults
March 22, 2019 - Adolescent daily users more likely to obtain electronic cigarettes from commercial sources
March 22, 2019 - FDA Approves Genentech’s Tecentriq in Combination With Chemotherapy for the Initial Treatment of Adults With Extensive-Stage Small Cell Lung Cancer
March 22, 2019 - Diabetes myths and facts: MedlinePlus Medical Encyclopedia
March 22, 2019 - TGen and ABL pursue global rollout of advanced TB test
March 22, 2019 - Traffic light labels influence people to choose healthier and more sustainable meals
March 22, 2019 - Alzheimer’s patients using antiepileptic drugs have twice the risk of pneumonia, study shows
March 22, 2019 - Skin diseases may be more prevalent than previously thought
March 22, 2019 - Overall rates of death from breast cancer are falling across the EU
March 22, 2019 - Novel plasmid could hold key to control of mosquito-borne illness
March 22, 2019 - Female Emergency Physicians Paid Less Than Males
March 22, 2019 - Estimated average glucose (eAG): MedlinePlus Medical Encyclopedia
March 22, 2019 - Experimental drug could be new option for type 2 diabetes
March 22, 2019 - Five Things To Know About The Electronic Health Records Mess
March 22, 2019 - TMJ disorders could be treated with tissue-engineered implants after successful animal study
March 22, 2019 - Team-based approach is key to successful care of pregnant women with heart failure
March 22, 2019 - Study identifies gene variant associated with accelerated cellular aging
March 21, 2019 - Salk scientists show how background noise from neurons can interrupt focused attention
March 21, 2019 - New class of drugs could help treat patients diagnosed with ovarian cancer
March 21, 2019 - Tecentriq Approved for Small Cell Lung Cancer
March 21, 2019 - Adipocyte glucocorticoid receptors play a role in developing steroid diabetes
March 21, 2019 - Climate change can affect nutrient content of crops, harming human health
March 21, 2019 - Podcast: KHN’s ‘What The Health’ Surprise! Fixing Surprise Medical Bills Is Harder Than it Looks
March 21, 2019 - Chemistry researchers patent new method for making anti-leukemia compounds
March 21, 2019 - UIC scientists identify hidden proteins in bacteria
March 21, 2019 - New Australian drug trial achieves remarkable results in patients with acute myeloid leukemia
March 21, 2019 - Females live longer when they have help raising offspring
March 21, 2019 - How did orthodontists sell orthodontics?
March 21, 2019 - In the Spotlight: From dietitian to physician assistant student
March 21, 2019 - The CRISPR Revolution: What You Need to Know
March 21, 2019 - FDA Chief Calls For Stricter Scrutiny Of Electronic Health Records
March 21, 2019 - Combined glucocorticoid and antioxidant therapy could benefit premature babies
March 21, 2019 - Low levels of certain eye proteins could serve as predictor for Alzheimer’s
March 21, 2019 - Post-traumatic holocaust survivors transmit negative views on aging to offspring
March 21, 2019 - City of Hope receives $7.5 million in grant awards to study cutaneous T cell lymphoma
March 21, 2019 - New video game-led training device helps stroke survivors regain arm mobility
March 21, 2019 - Compounds in coffee could slow prostate cancer growth
March 21, 2019 - New mobile DNA element in Wolbachia may contribute to improved disease control strategies
March 21, 2019 - Phase 2 Clinical Trial of Bermekimab Shows Potential New Standard of Care for Treatment of Hidradenitis Suppurativa, Including Significant Pain Reduction without Antibiotics
March 21, 2019 - More than one-third of patients risk major bleeding by doubling up on blood thinners
March 21, 2019 - A skeptical look at popular diets: Thumbs up for Mediterranean
March 21, 2019 - PTSD After Cardiac Arrest Predicts More Heart Trouble
March 21, 2019 - Role of immunological imprinting in elicitation of new antibodies
March 21, 2019 - Breast cancer relapse predictor tool may soon be a reality
March 21, 2019 - New computer program developed by TGen lights up cancer-causing genetic mutations
March 21, 2019 - FDA warns two breast implant makers for failure to comply with post-approval study requirements
March 21, 2019 - Butler Hospital receives COBRE grant to enhance research on neuropsychiatric illnesses
March 21, 2019 - Majority of osteoporosis clinical practice guidelines ignore patients’ voices
March 21, 2019 - Generic messages don’t help patients to lose weight
March 21, 2019 - Eisai and Imbrium Therapeutics Announce U.S. FDA Filing Acceptance of New Drug Application for Lemborexant for the Treatment of Insomnia
March 21, 2019 - Two-drug combos using popular calcium channel blocker show superiority in lowering BP
Stick insect study reveals importance of small limbs’ passive muscle force for swift movements

Stick insect study reveals importance of small limbs’ passive muscle force for swift movements

image_pdfDownload PDFimage_print

Long, heavy limbs such as arms or legs differ fundamentally from short, light limbs such as fingers in their ability to execute fast movements. While the central nervous system has to actively control fast movements of large limbs, passive muscle force can suffice for the movement velocity and movement amplitude of small and light limbs. That is the result of a study conducted on the stick insect by the zoologists Ansgar Bueschges, Arndt von Twickel and Christoph Guschlbauer at the University of Cologne in cooperation with the visiting scientist Scott Hooper from Ohio University. The paper has now been published under the title ‘Swing Velocity Profiles of Small Limbs Can Arise from Transient Passive Torques of the Antagonist Muscle Alone’ in Current Biology.

There are different basic speed levels in the course of a movement until the entire motor action has been optimally executed, says Bueschges: ‘If we look at the swinging of our legs when we walk, for example, the swinging phase brings the leg back into the starting position for the next step. With this feedback, the swing speed of the leg decreases towards the end, so that the foot does not touch down as quickly. Without the deceleration, the force generated when touching down would be so strong that it would counteract the next step.’ Our nervous system produces this deceleration in large limbs such as the human leg.

For smaller limbs such as insect bones, however, the authors have shown that the slowing of the leg during rapid movements such as the swinging phase is independent of the central nervous system. Von Twickel explains that this is due to the intrinsic muscle characteristics of the limb: ‘If the extensor muscle of a leg joint is actively shortened to produce rapid movements, the inactive flexor muscle is necessarily lengthened. During this stretching, the flexor muscle develops a previously unknown dynamic passive force, which is so large that it can continuously slow down movements to the functionally necessary level.’

In the study, the authors exposed the flexor muscle of the stick insect leg to various stretching scenarios and measured the dynamic forces exerted by the passive muscle against the different stretches. Then, they used the results to dynamically simulate the functioning of a leg joint. The passive dynamic forces of the flexor generated by extensor activation were able to generate a movement that corresponded to the speed profile of an animal.

These results are quite surprising and contradict widespread notions of how small limbs execute fast movements. Bueschges concludes: ‘We have known for a long time that passive muscle forces are important for the movements of small limbs, but we did not expect that their effect is so great that they can determine the speed profile of a movement. This means that the active muscle and its opponent must be perfectly tuned to each other. We are in the process of better understanding this interaction.’

Tagged with:

About author

Related Articles