Anticipation of drop height affects neuromuscular control and muscle‐tendon mechanics

2019 ◽  
Vol 30 (1) ◽  
pp. 46-63 ◽  
Author(s):  
Michael Helm ◽  
Kathrin Freyler ◽  
Janice Waldvogel ◽  
Benedikt Lauber ◽  
Albert Gollhofer ◽  
...  
Keyword(s):  
Neuromuscular Control ◽  
Drop Height ◽  
Tendon Mechanics

scholarly journals The series elastic shock absorber: tendon elasticity modulates energy dissipation by muscle during burst deceleration

2015 ◽  
Vol 282 (1804) ◽  
pp. 20142800 ◽  
Author(s):  
Nicolai Konow ◽  
Thomas J. Roberts
Keyword(s):  
Energy Dissipation ◽  
Shock Absorber ◽  
Mechanical Energy ◽  
Reaction Force ◽  
Drop Height ◽  
Fascicle Length ◽  
Tendon Mechanics ◽  
Rapid Adjustment ◽  
Relationship Of ◽  
Tendon Compliance

During downhill running, manoeuvring, negotiation of obstacles and landings from a jump, mechanical energy is dissipated via active lengthening of limb muscles. Tendon compliance provides a ‘shock-absorber’ mechanism that rapidly absorbs mechanical energy and releases it more slowly as the recoil of the tendon does work to stretch muscle fascicles. By lowering the rate of muscular energy dissipation, tendon compliance likely reduces the risk of muscle injury that can result from rapid and forceful muscle lengthening. Here, we examine how muscle–tendon mechanics are modulated in response to changes in demand for energy dissipation. We measured lateral gastrocnemius (LG) muscle activity, force and fascicle length, as well as leg joint kinematics and ground-reaction force, as turkeys performed drop-landings from three heights (0.5–1.5 m centre-of-mass elevation). Negative work by the LG muscle–tendon unit during landing increased with drop height, mainly owing to greater muscle recruitment and force as drop height increased. Although muscle strain did not increase with landing height, ankle flexion increased owing to increased tendon strain at higher muscle forces. Measurements of the length–tension relationship of the muscle indicated that the muscle reached peak force at shorter and likely safer operating lengths as drop height increased. Our results indicate that tendon compliance is important to the modulation of energy dissipation by active muscle with changes in demand and may provide a mechanism for rapid adjustment of function during deceleration tasks of unpredictable intensity.

scholarly journals Foot Structure and Muscle Reaction Time to a Simulated Ankle Sprain

2013 ◽  
Vol 48 (3) ◽  
pp. 326-330 ◽  
Author(s):  
Joanna R. Denyer ◽  
Naomi L. A. Hewitt ◽  
Andrew C. S. Mitchell
Keyword(s):  
Reaction Time ◽  
Ankle Sprain ◽  
Tibialis Anterior ◽  
Reaction Times ◽  
Neuromuscular Control ◽  
Gluteus Medius ◽  
Drop Height ◽  
Peroneus Longus ◽  
Foot Structure ◽  
Navicular Drop

Context: Foot structure has been shown to affect aspects of neuromuscular control, including postural stability and proprioception. However, despite an association between pronated and supinated foot structures and the incidence of lateral ankle sprains, no one to our knowledge has measured muscle reaction time to a simulated ankle-sprain mechanism in participants with different foot structures. Objective: To determine whether pronated or supinated foot structures contribute to neuromuscular deficits as measured by muscle reaction time to a simulated ankle-sprain mechanism. Design: Cross-sectional study. Setting: University biomechanics laboratory. Patients or Other Participants: Thirty volunteers were categorized into 3 groups according to navicular-drop–height measures. Ten participants (4 men, 6 women) had neutral feet (navicular-drop height = 5–9 mm), 10 participants (4 men, 6 women) had pronated feet (navicular-drop height ≥ 10 mm), and 10 participants (4 men, 6 women) had supinated feet (navicular-drop height ≤ 4 mm). Intervention(s): Three perturbations on a standing tilt platform simulating the mechanics of an inversion and plantar-flexion ankle sprain. Main Outcome Measure(s): Muscle reaction time in milliseconds of the peroneus longus, tibialis anterior, and gluteus medius to the tilt-platform perturbation. Results: Participants with pronated or supinated foot structures had slower peroneus longus reaction times than participants with neutral feet (P = .01 and P = .04, respectively). We found no differences for the tibialis anterior or gluteus medius. Conclusions: Foot structure influenced peroneus longus reaction time. Further research is required to establish the consequences of slower peroneal reaction times in pronated and supinated foot structures. Researchers investigating lower limb muscle reaction time should control for foot structure because it may influence results.

Functional Anatomy Underlying Pharyngeal Swallowing Mechanics and Swallowing Performance Goals

2019 ◽  
Vol 4 (4) ◽  
pp. 648-655
Author(s):  
William G. Pearson ◽  
Jacline V. Griffeth ◽  
Alexis M. Ennis
Keyword(s):  
Functional Anatomy ◽  
Neuromuscular Control ◽  
Upper Esophageal Sphincter ◽  
Performance Goals ◽  
Laryngeal Elevation ◽  
Port Closure ◽  
Swallowing Dysfunction ◽  
Hyoid Movement ◽  
Pharyngeal Swallowing ◽  
Pharyngeal Constriction

Purpose Rehabilitation of pharyngeal swallowing dysfunction requires a thorough understanding of the functional anatomy underlying the performance goals of pharyngeal swallowing. These goals include the safe and efficient transfer of a bolus through the hypopharynx into the esophagus. Penetration or aspiration of a bolus threatens swallowing safety. Bolus residue indicates swallowing inefficiency. Several primary mechanics, or elements of the swallowing mechanism, underlie these performance goals, with some elements contributing to both goals. These primary mechanics include velopharyngeal port closure, hyoid movement, laryngeal elevation, pharyngeal shortening, tongue base retraction, and pharyngeal constriction. Each element of the swallowing mechanism is under neuromuscular control and is therefore, in principle, a potential target for rehabilitation. Secondary mechanics of pharyngeal swallowing, those movements dependent on primary mechanics, include opening the upper esophageal sphincter and epiglottic inversion. Conclusion Understanding the functional anatomy of pharyngeal swallowing underlying swallowing performance goals will facilitate anatomically informed critical thinking in the rehabilitation of pharyngeal swallowing dysfunction.

Safety And Preliminary Efficacy of Magnetic Stimulation of Pelvic Floor with Hifem Technology in Urinary Incontinence

2018 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Urinary Incontinence ◽  
Pelvic Floor ◽  
Magnetic Stimulation ◽  
Muscle Tone ◽  
Pelvic Floor Muscle ◽  
Neuromuscular Control ◽  
Ultrasound Elastography ◽  
Functional Evaluation ◽  
Muscle Injuries ◽  
Stimulation Of

Introduction: BTL EMSELLA™ utilizes High-Intensity Focused Electromagnetic technology (HIFEM) to cause deep pelvic floor muscles stimulation and restoration of the neuromuscular control. Key effectiveness is based on focused electromagnetic energy, in-depth penetration and stimulation of the entire pelvic floor area. A single BTL EMSELLA™ session brings thousands of supramaximal pelvic floor muscle contractions, which are extremely important in muscle reeducation of incontinent patients. Objective: Prospective study to evaluate the safety and preliminary effectiveness of the use of BTL EMSELLA magnetic stimulation in urinary incontinence. Method: Thirty-two patients with light and moderate urinary incontinence were recruited to perform 6 sessions of BTL EMSELLA during three weeks of initial treatment. Follow-up after three months. The patients received sessions lasting 28 minutes, completing the different treatment protocols. Initially the patients underwent a quality of life test before and after treatment, evaluation with advanced ultrasound using elastography to measure the initial tissue's elasticity and be able to compare after treatment, clinical functional evaluation and urodynamic test. Results: No adverse reactions were observed. All the patients finished the treatment sessions. Two patients reported increased pain after treatment in the first session corresponding to a VAS scale greater than 5 with duration greater than three hours. The treatment was highly satisfactory in 84,4% of the patients. After the first three months the improvement was maintained in 77% of the patients. No muscle injuries were observed. Elastographic changes and improvement of muscle tone were detected by advanced ultrasound (elastography) in 100% of patients. Conclusions: BTL EMSELLA is safe, well tolerated and effective for the treatment of mild and moderate urinary incontinence. The observed elastographic changes demonstrate the improvement of pelvic floor muscle tone after treatment. A reduction in the symptoms of urinary incontinence was demonstrated. Recommendations: Continue increasing the number of cases for research and increase the variables that we have decided to incorporate in the next research section such as MRI and pressure calculation.

Neuromuscular Control of Movement

2018 ◽  
Keyword(s):  
Nervous System ◽  
Sensory Information ◽  
Neuromuscular Control ◽  
Complex Environments ◽  
Locomotor Rhythm ◽  
Motor Responses ◽  
Reflex Pathways ◽  
Local Reflex ◽  
Local Circuits ◽  
And Control

The control of movement is essential for animals traversing complex environments and operating across a range of speeds and gaits. We consider how animals process sensory information and initiate motor responses, primarily focusing on simple motor responses that involve local reflex pathways of feedback and control, rather than the more complex, longer-term responses that require the broader integration of higher centers within the nervous system. We explore how local circuits facilitate decentralized coordination of locomotor rhythm and examine the fundamentals of sensory receptors located in the muscles, tendons, joints, and at the animal’s body surface. These sensors monitor the animal’s physical environment and the action of its muscles. The sensory information is then carried back to the animal’s nervous system by afferent neurons, providing feedback that is integrated at the level of the spinal cord of vertebrates and sensory-motor ganglia of invertebrates.

scholarly journals Neurophysiological changes of brain and spinal cord in individuals with patellofemoral pain: a systematic review and meta-analysis protocol

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e049882
Author(s):  
Jing Nong Liang ◽  
Savanna Budge ◽  
Austin Madriaga ◽  
Kara Meske ◽  
Derrick Nguyenton ◽  
...  
Keyword(s):  
Systematic Review ◽  
Spinal Cord ◽  
Quality Assessment ◽  
Meta Analysis ◽  
Neuromuscular Control ◽  
Patellofemoral Pain ◽  
Randomised Control Trial ◽  
Cross Sectional ◽  
Prospective Longitudinal ◽  
Brain And Spinal Cord

IntroductionReduced neuromuscular control due to altered neurophysiological functions of the central nervous system has been suggested to cause movement deficits in individuals with patellofemoral pain (PFP). However, the underlying neurophysiological measures of brain and spinal cord in this population remain to be poorly understood. The purpose of this systematic review is to evaluate the evidence for altered cortical and spinal cord functions in individuals with PFP.Methods and analysisThe protocol for conducting the review was prepared using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. We will systematically search the literature that examines cortical and spinal cord functions in individuals with PFP, aged 18–45 years. The studies for cross-sectional, prospective, longitudinal, case–control and randomised control trial designs will be included from the following databases: PubMed (MEDLINE), EMBASE and Web of Science. Only studies published in English prior to 1 February 2021 will be included. The risk of bias and quality assessment will be performed using National Institutes of Health’s Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. We will conduct meta-analysis of the data where appropriate. Narrative synthesis will be taken if a meta-analysis is not possible.Ethics and disseminationThis is a systematic review from the existing literature and does not require ethical approval. The results of this study will be published in a peer-reviewed journal in the field of rehabilitation medicine, sports/orthopaedic medicine or neurology, regardless of the outcome.PROSPERO registration numberCRD42020212128.

scholarly journals Application of a Preventive Training Program Implementation Framework to Youth Soccer and Basketball Organizations

2019 ◽  
Vol 54 (2) ◽  
pp. 182-191 ◽  
Author(s):  
Hayley J. Root ◽  
Barnett S. Frank ◽  
Craig R. Denegar ◽  
Douglas J. Casa ◽  
David I. Gregorio ◽  
...  
Keyword(s):  
Program Implementation ◽  
Administrative Support ◽  
Neuromuscular Control ◽  
Initial Step ◽  
Sport Performance ◽  
Implementation Framework ◽  
Injury Rates ◽  
Youth Soccer ◽  
Youth Athletes ◽  
Education Workshop

Context Preventive training programs (PTPs) can reduce injury rates and improve neuromuscular control and sport performance. However, PTPs must be implemented correctly and consistently over time for athletes to benefit. Coaches represent the best long-term option for implementing PTPs. Youth athletes are at the optimal age for developing good habits before maturation. Although frameworks have been proposed to guide implementation efforts, little is known regarding the feasibility and real-world context of PTP implementation at the youth sport level. Objective To evaluate the application of the 7-Step framework for promoting implementation of a preseason PTP workshop. Design Descriptive epidemiology study. Setting Youth soccer and basketball organizations. Patients or Other Participants Organizations with at least 1 team of athletes aged 8 to 14 years were invited to participate in a free preseason coaches' education workshop on PTP implementation. Intervention(s) The 7-Step framework was used to guide PTP education and implementation for each organization. Personnel at organizations that agreed to participate attended a single preseason workshop for coaches. Research staff were available as a resource throughout the season but did not actively implement or monitor the PTPs. Main Outcome Measure(s) Retrospective evaluation of each organization's completion of steps 1 through 5 of the 7-Step framework. Results A total of 62 youth soccer (n = 40) and basketball (n = 22) organizations were invited to participate. Twelve organizations completed steps 1 through 4 and steps 5a through 5d. The highest drop-off rate occurred during step 1, “Establishing Administrative Support.” No organization completed all components of steps 1 through 5. Conclusions To better understand how to successfully promote PTP adoption, we must identify the implementation steps that may present the most challenges. Because the highest drop-off rate was seen during the initial step, establishing administrative support and strengthening initial engagement are necessary to improve PTP implementation.

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