scholarly journals Tibial lengthening in achondroplasia patients aged 6–9 years as the first stage of growth correction

2021 ◽  
Vol 27 (3) ◽  
pp. 366-371
Author(s):  
T.I. Menshchikova ◽  
◽  
A.M. Aranovich ◽  
Keyword(s):  
Tibialis Anterior ◽  
Extensor Digitorum Longus ◽  
Plantar Flexion ◽  
Contractile Force ◽  
Extensor Digitorum ◽  
Spare Capacity ◽  
Preoperative Level ◽  
Imaging Device ◽  
Tibial Lengthening ◽  
Anterior Tibial

Background Height increase and improvement of body proportions for achondroplasia patients normally require two or more stages of reconstructive treatment to be followed by rehabilitation between lengthening periods, and growth correction can take a significant part of life in the cohort of patients. What is the best age to start growth correction is an important question. The purpose of this paper was to present an argument for arranging the first stage of growth correction in achondroplasia patients aged 6–9 years based on the structural and functional muscle evaluation of tibiae to be lengthened. Material and methods Achondroplasia patients aged 6–9 years (n = 30) were examined preoperatively, during distraction, fixation and at 1.5 to 2 years of frame removal. Tibial lengthening was produced monofocally and bifocally. Contractile force of the dorsal and plantar flexion muscles of the foot was measured with dynamometer. Ultrasonography of tibial muscles was performed with HITACHI ultrasound imaging device (Japan). Results Achondroplasia patients aged 6–9 year who underwent tibial lengthening of at least 50% of the initial length developed neuropathy in 2.6 % of cases and soft tissue inflammation in 5.6 % of cases. Characteristic muscle striation of m. tibialis anterior and m. extensor digitorum longus appeared to restore at 1.5 to 2 years of tibial lengthening with clear contouring of the intermuscular septa and retained contractile force of the muscles. The contractile force restored to 96.15 % of preoperative level in the anterior tibial muscles, and to 101.92 % in the posterior muscles. Conclusion The comprehensive clinical, ultrasonographic and dynamometric evaluation of tibial muscles presented a good argument for tibial lengthening in achondroplasia patients aged 6–9 years. Regained muscle striation and spare capacity of m. tibialis anterior and extensor digitorum longus, the restored force of the anterior tibial muscles to 96.15 % of the preoperative level suggested the possibility for the next stage of growth correction.

Alterations in intramuscular connective tissue after limb casting affect contraction-induced muscle injury

1995 ◽  
Vol 78 (3) ◽  
pp. 1065-1069 ◽  
Author(s):  
T. K. Lapier ◽  
H. W. Burton ◽  
R. Almon ◽  
F. Cerny
Keyword(s):  
Connective Tissue ◽  
Muscle Injury ◽  
Extensor Digitorum Longus ◽  
Plantar Flexion ◽  
Extensor Digitorum ◽  
Control Group ◽  
Longus Muscle ◽  
Limb Immobilization

This study examined the effect of alterations in rat intramuscular connective tissue (CT), secondary to limb immobilization, on the muscle's susceptibility to contraction-induced injury. Hindlimbs were casted for 3 wk with the extensor digitorum longus muscle fixed in a shortened (IM-SP) or lengthened position (IM-LP). An age-matched control group remained uncasted. Extensor digitorum longus muscles were injured in vivo by using a motorized foot pedal that repeatedly flexed and extended the foot while the muscle was electrically stimulated during plantar flexion. Four hours postinjury, maximum isometric tetanic force (Po) was measured in vitro and was used as a functional index of muscle injury. Muscles were fixed, sectioned, and stained for later analysis. Intramuscular CT concentration, expressed as the ratio of CT area to muscle fiber area, was significantly higher in both IM-SP (0.153 +/- 0.003) and IM-LP (0.174 +/- 0.003) groups compared with controls (0.104 +/- 0.003). Po values of injured muscles both IM-LP and IM-SP were higher than the injured controls' Po of 9.41 +/- 0.63 N/cm2 (P < 0.05). Injured IM-LP muscle forces were significantly higher than those of IM-SP. This study demonstrated that limb immobilization increases intramuscular CT concentration, which is accompanied by attenuation of muscle injury. We conclude that remodeling of intramuscular CT affects the muscle's resistance to contraction-induced injury.

scholarly journals Effects of re-feeding after prolonged starvation on pyruvate dehydrogenase activities in heart, diaphragm and selected skeletal muscles of the rat

1989 ◽  
Vol 262 (2) ◽  
pp. 669-672 ◽  
Author(s):  
M C Sugden ◽  
M J Holness
Keyword(s):  
Skeletal Muscle ◽  
Pyruvate Dehydrogenase ◽  
Tibialis Anterior ◽  
Skeletal Muscles ◽  
Extensor Digitorum Longus ◽  
Glycogen Synthesis ◽  
Extensor Digitorum ◽  
Hepatic Glycogen ◽  
Prolonged Starvation ◽  
Adductor Longus

We investigated the capacity for pyruvate oxidation in skeletal muscle, diaphragm and heart after starvation and re-feeding. Starvation for 48 h decreased pyruvate dehydrogenase (PDH) activity in soleus (by 47%), extensor digitorum longus (64%), gastrocnemius (86%), diaphragm (87%), adductor longus (90%), tibialis anterior (92%) and heart (99%). Chow re-feeding increased PDH activity in all muscles to 43-78% of the fed value within 2 h. However, complete re-activation was not observed for at least 4-6 h, during which time hepatic glycogen was replenished. We discuss the importance of muscle PDH activity in relation to sparing carbohydrate for hepatic glycogen synthesis.

High-energy phosphates and tension production in rabbit tibialis anterior/extensor digitorum longus muscles

1997 ◽  
Vol 82 (3) ◽  
pp. 1024-1024 ◽  
Author(s):  
T. W. Ryschon ◽  
J. C. Jarvis ◽  
S. Salmons ◽  
R. S. Balaban
Keyword(s):  
Tibialis Anterior ◽  
Extensor Digitorum Longus ◽  
Energy State ◽  
Oxidative Capacity ◽  
High Energy ◽  
Extensor Digitorum ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Control Muscle

Ryschon, T. W., J. C. Jarvis, S. Salmons, and R. S. Balaban.High-energy phosphates and tension production in rabbit tibialis anterior/extensor digitorum longus muscles. J. Appl. Physiol. 82(3): 1024–1029, 1997.—The effects of repetitive muscle contraction on energy state and tension production were studied in rabbit tibialis anterior/extensor digitorum longus muscles that had been subjected to 90 days of continuous indirect electrical stimulation at 10 Hz. Anesthetized chronically stimulated and control rabbits were challenged with 15 min of stimulation at 4 and 15 tetani/min. Pi-to-phosphocreatine (PCr) ratio (Pi/PCr) was measured in vivo before, during, and after acute stimulation by31P-magnetic resonance spectroscopy, and tension was recorded at the same time. Although Pi/PCr was low at rest, it was significantly higher in chronically stimulated muscle than in control muscle (0.20 ± 0.02 vs. 0.05 ± 0.01, P < 0.05). Stimulation of control muscle for 15 min at both 4 and 15 tetani/min induced a significant rise in Pi/PCr, whereas the same conditions in chronically stimulated muscle did not produce any significant departure from initial levels. The tension produced by control muscle fell to 93 ± 3% of its initial value during stimulation at 4 tetani/min and to 61 ± 7% at 15 tetani/min, respectively. In chronically stimulated muscle, on the other hand, tension was potentiated above its initial level at both stimulation rates (135 ± 15 and 138 ± 11%, respectively) and remained significantly elevated throughout each trial. The ability of chronically stimulated muscle to sustain high levels of activity with minimal perturbations in Pi/PCr or decrement in tension is attributable to cellular adaptations that include a well-documented increase in oxidative capacity.

scholarly journals Isolated partial tear of extensor digitorum longus tendon with overlying muscle herniation in acute ankle sports injury: role of high resolution musculoskeletal ultrasound

2021 ◽  
Author(s):  
Jeena Bordoloi Deka ◽  
Nilim Kumar Deka ◽  
Mohit V. Shah ◽  
Chandra Bortolotto ◽  
Ferdinando Draghi ◽  
...  
Keyword(s):  
Ankle Sprain ◽  
Extensor Digitorum Longus ◽  
Plantar Flexion ◽  
Extensor Digitorum ◽  
Return To Play ◽  
Lateral Ankle Sprain ◽  
Lateral Ankle ◽  
Partial Tear ◽  
Early Return ◽  
Lateral Ankle Ligaments

AbstractLateral Ankle sprain is a common sports-related trauma with the mechanism of injury ranging from inversion to plantar flexion. These injuries commonly affect the ligaments but can also affect the associated soft tissue structures like the eversion muscles and tendons. Prompt and accurate diagnosis of such injuries is warranted so as to ensure early return to play and prevent long-term complications. Lateral ankle sprain injuries in sports may not always be associated with ligament injuries. We report a never before reported case of lateral ankle sprain injury in a soccer player with the unusual finding of isolated partial tear of Extensor digitorum longus muscle and its fascia leading to myo-fascial herniation. The lateral ankle ligaments were intact. The diagnosis was clinched on a high-frequency ultrasound scan supported by dynamic maneuvers which in fact proved to be superior to MRI as the latter failed to demonstrate the myo-fascial herniation in our case. We therefore propose that real-time ultrasound scanning with dynamic maneuvers should be the first line of investigation to assess sports injuries in anatomically complex joints like the ankle.

Positive Proprioceptive Feedback Elicited By Isometric Contractions of Ankle Flexors on Pretibial Motoneurons in Cats

2002 ◽  
Vol 88 (5) ◽  
pp. 2207-2214 ◽  
Author(s):  
L. Brizzi ◽  
L. H. Ting ◽  
D. Zytnicki
Keyword(s):  
Electrical Stimulation ◽  
Positive Feedback ◽  
Tibialis Anterior ◽  
Extensor Digitorum Longus ◽  
Motor Units ◽  
Extensor Digitorum ◽  
Isometric Contractions ◽  
Postsynaptic Potentials ◽  
Group I ◽  
Stimulation Of

Pretibial flexor motoneurons were recorded intracellularly in anesthetized cats during unfused isometric contractions of a subpopulation of motor units from either tibialis anterior (TA) or extensor digitorum longus (EDL) muscles. The contractions elicited excitatory postsynaptic potentials in 23 of 28 pretibial flexor motoneurons. No effect was observed in the remaining motoneurons. In control experiments, the effects of electrical stimulation of afferents within the TA nerve were investigated to help identify afferents responsible for the contraction-induced positive feedback. This feedback was ascribed to actions of Ia fibers because the pattern of the contraction-induced excitatory potentials was consistent with the known pattern of Ia discharge; in control experiments, electrical stimulation of group I fibers elicited only monosynaptic excitatory potentials; and the distribution of both the contraction-induced positive feedback among motor nuclei as well as the electrically evoked Ia excitatory monosynaptic potentials were restricted to homonymous and synergic motoneurons. Observation of the Ia contraction-induced positive feedback was facilitated by the absence of Ib autogenic inhibition. This contraction-induced Ia excitatory feedback in ankle flexors might either reinforce Ia-induced reflexes when these muscles are lengthened or help to lift the leg over an obstacle.

Effect of overexpressing GLUT-1 and GLUT-4 on insulin- and contraction-stimulated glucose transport in muscle

1996 ◽  
Vol 271 (3) ◽  
pp. E547-E555 ◽  
Author(s):  
E. Johannsson ◽  
K. J. McCullagh ◽  
X. X. Han ◽  
P. K. Fernando ◽  
J. Jensen ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Glucose Transport ◽  
Tibialis Anterior ◽  
Skeletal Muscles ◽  
Extensor Digitorum Longus ◽  
Muscle Contractions ◽  
Extensor Digitorum ◽  
Glut 1 ◽  
Glut 4 ◽  
Chronic Electrical Stimulation

To examine the effects of GLUT-1 on GLUT-4-dependent, insulin-stimulated, and contraction-stimulated 2-deoxy-D-glucose (2-DG) transport, we overexpressed GLUT-1 in metabolically heterogeneous skeletal muscles [red and white tibialis anterior (TA) and extensor digitorum longus (EDL)] via 7 days of chronic electrical stimulation. GLUT-1 was increased 1.6- to 16.4-fold (P < 0.05). Basal 2-DG transport was increased 1.7- to 3.0-fold (P < 0.05) and was equal to (red TA and EDL; P > 0.05) or exceeded insulin-stimulated 2-DG transport by 50% (white TA; P < 0.05) in the control muscles. GLUT-4 was concomitantly overexpressed (2.1- to 4.4-fold; P < 0.05). Insulin-stimulated 2-DG transport was increased 1.6- to 2.5-fold (P < 0.05). During muscle contractions, 2-DG transport increased 9- to 12-fold (P < 0.05) in control muscles, but this was reduced by approximately 25% (P < 0.05) in muscles overexpressing GLUT-1 and GLUT-4 (red TA and EDL). In contrast, in the experiment, white TA contraction-stimulated 2-DG transport was increased 1.7-fold (P < 0.05). Therefore, overexpression of GLUT-1, when GLUT-4 is also overexpressed, does not impair insulin-stimulated 2-DG transport, although contraction-stimulated transport may be reduced in some muscles.

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