Sensory contributions to control
Andrea Utley in Motor Control, Learning and Development, 2018
Deafferentation can also arise without surgery. For example, sensory polyneuropathy results in a loss of all sensory information (except for pain and temperature) due to the loss of, or demyelination of, large sensory fibers. The efferent fibers, however, are usually left intact. Mazzaro et al. (2005) examined the effect of dorsiflexion enhancements and reductions applied to patients with demyelination of large sensory fibers and age-matched controls during the stance phase of the gait cycle. This experimental procedure was designed to examine the contribution of these large-diameter sensory fibers to the adaptation of soleus muscle activity after small ankle trajectory modifications during human walking. In healthy subjects, the soleus electromyogram (EMG) gradually increased or decreased when the ankle dorsiflexion was, respectively, enhanced or reduced. Similarly, the soleus EMG activity in the patients increased during the dorsiflexion enhancements; however, the velocity sensitivity was decreased compared with the healthy volunteers. In addition, when dorsiflexion was reduced, the soleus EMG activity was unchanged. These data showed how important sensory feedback in the form of proprioception is for the continuous adaptation of soleus activity during the stance phase of walking.
Podiatric Medicine and the Painful Heel
Mark V. Boswell, B. Eliot Cole in Weiner's Pain Management, 2005
One method to assess for calf tightness is to apply a heel lift (on the painful foot) that does not compress to less than 1/2 to 1 in. If the plantar heel pain eases, then calf tightness must be addressed in the process of eliminating heel pain. If calf tightness is noted, it is best to stretch the Achilles tendon bilaterally. The stretch should be done with the subtalar joint of the foot in neutral position. This helps to maximize the stretch of the Achilles tendon. The stretches should be done with static holds, without bouncing. If heel lifts are needed, then the lifts should be worn in both shoes to reduce the risk of back pain until the flexibility of the gastro-soleus complex is restored. When bouncing instead of static stretching is done during exercise, shortening of the gastro-soleus muscle area is apt to occur. This shortening may cause a secondary Achilles tendonitis.
Noninsulin-Dependent Animal Models of Diabetes Mellitus
John H. McNeill in Experimental Models of Diabetes, 2018
First-phase insulin responses to glucose are decreased in vivo,267,371 whereas integrated responses to other stimuli are increased. This has been interpreted as indicating a general secretory abnormality,267 However, several in vitro studies point to a selective defect in glucose-induced insulin secretion.273 It is unclear if such defects are primary or secondary to chronic hyperinsulinemia and hyperglycemia. Insulin resistance occurs at 4 to 5 weeks in several tissues,272 the origin of which has also been investigated in a number of studies. At 4 to 6 weeks of age, glucose uptake and utilization in soleus muscle in the absence of insulin is reduced, but there is a normal response to insulin.263 However, from 11 weeks, insulin responsiveness is markedly impaired. Na+-K+-pump activity is also reduced in soleus muscle from NZO mice.274 Changes in the intrinsic metabolic rate of skeletal muscle probably play an important role in the control of overall energy balance, and may be partly responsible for the altered energetic efficiency in this strain of mice. The liver also demonstrates insulin resistance, and hepatic glucose production is increased at an early age.272,275,276 There appears to be an abnormality in fructose-1,6-bisphosphatase activity277 and a failure in the normal mechanisms that reduce levels of glycogen synthase following birth,278 which may contribute to the increased hepatic glucose production.
Effect of inhibitory kinesiotaping on spasticity in patients with chronic stroke: a randomized controlled pilot trial
Published in Topics in Stroke Rehabilitation, 2022
Mahdad Mehraein, Zahra Rojhani- Shirazi, Ahmad Zeinali Ghotrom, Nasrin Salehi Dehno
Taping was employed by a qualified physical therapist in accordance with the recommendations of the Kenzo Kase’s kinesiology taping manual.15 A Y-shaped strip of KT (3NS TEX Tape, 3NS Inc, Korea) was applied to the calf muscles (Gastrocnemius/Soleus) from insertion to the origin of muscles with 25% of its maximal length tension in order to induce inhibitory effect. The basis of Y was anchored on calcaneus without tension with the subject in a prone position with the knee extended and the ankle in a neutral position. Afterward, the ankle was dorsi-flexed and the medial and lateral tails of Y were attached following the soleus muscle and the medial and lateral sides of gastrocnemius muscle.15 During ankle dorsiflexion, the therapist should not provoke spinal reflexes by touching the patient’s sole (Figure 1).
Cognitive function is preserved in aged mice following long-term β-hydroxy β-methylbutyrate supplementation
Published in Nutritional Neuroscience, 2020
Michael Munroe, Ziad S. Mahmassani, Svyatoslav Dvoretskiy, Justin J. Reid, Benjamin F. Miller, Karyn Hamilton, Justin S. Rhodes, Marni D. Boppart
After 24 weeks, mice were fully anesthetized using isoflurane and blood was collected via cardiac puncture. Gastrocnemius-soleus muscle complexes were then excised and muscle weight was recorded. One complex was immersed in ice-cold 1× PBS plus penicillin/streptomycin and used for pericyte isolation. The other muscle complex was snap frozen in liquid nitrogen to be used for protein synthesis analysis. The brain was then dissected and immersed in ice-cold MEM with HEPES modification (Sigma-Aldrich, St Louis, MO) and used for pericyte isolation. Collected blood was allowed to clot in a 2.0 mL Eppendorf tube for 30 minutes at room temperature then centrifuged at 1200×g for 10 minutes at 4°C. Serum supernatant was transferred to a new 1.5 mL Eppendorf tube and stored at −80°C.
Corticomotor Excitability of Gluteus Maximus Is Associated with Hip Biomechanics During a Single-Leg Drop-Jump
Published in Journal of Motor Behavior, 2021
Yo Shih, Beth E. Fisher, Jo Armour Smith, Christopher M. Powers
Movement behavior is a complex interaction between neural control, biomechanical capacity, and task demand. To address our hypothesis related to the motor control aspects of the drop jump task, we chose the slope of the IOC to quantify excitability of the descending corticospinal pathway. A larger slope of the IOC represents greater excitability and recruitment efficiency of a given muscle (Devanne, Lavoie, & Capaday, 1997; Kukke, Paine, Chao, de Campos, & Hallett, 2014). It should be noted however, that the IOC is affected by multiple regions along the descending corticospinal motor pathway, and as such, it could not be determined whether movement behavior as measured in the current study was mediated to a greater extent by cortical or spinal structures. However, there is evidence to suggest that different phases of the drop jump maneuver are modulated by different circuits. Taube et al. reported that the spinal contribution for the soleus muscle was strongest immediately following ground contact and progressively declined during the stance phase owing to the stretch reflex (Taube et al., 2008). In contrast, supraspinal/cortical contribution for the soleus muscle was higher during the push-off phase (Taube et al., 2008). It is possible that GM follows a similar pattern of modulation, however additional research would be necessary to clarify this hypothesis.
Related Knowledge Centers
- Fibula
- Gastrocnemius Muscle
- Muscle
- Triceps Surae Muscle
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- Leg
- Calf
- Knee
- Heel
- Posterior Compartment of Leg