An experimental study of low-level laser therapy in rat Achilles tendon injury

The aim of this controlled animal study was to investigate the effect of low-level laser therapy (LLLT) administered 30 min after injury to the Achilles tendon. The study animals comprised 16 Sprague Dawley male rats divided in two groups. The right Achilles tendons were injured by blunt trauma using a mini guillotine, and were treated with LLLT or placebo LLLT 30 min later. The injury and LLLT procedures were then repeated 15 hours later on the same tendon. One group received active LLLT (lambda = 904 nm, 60 mW mean output power, 0.158 W/cm(2) for 50 s, energy 3 J) and the other group received placebo LLLT 23 hours after LLLT. Ultrasonographic images were taken to measure the thickness of the right and left Achilles tendons. Animals were then killed, and all Achilles tendons were tested for ultimate tensile strength (UTS). All analyses were performed by blinded observers. There was a significant increase in tendon thickness in the active LLLT group when compared with the placebo group (p < 0.05) and there were no significant differences between the placebo and uninjured left tendons. There were no significant differences in UTS between laser-treated, placebo-treated and uninjured tendons. Laser irradiation of the Achilles tendon at 0.158 W/cm(2) for 50 s (3 J) administered within the first 30 min after blunt trauma, and repeated after 15 h, appears to lead to edema of the tendon measured 23 hours after LLLT. The guillotine blunt trauma model seems suitable for inflicting tendon injury and measuring the effects of treatment on edema by ultrasonography and UTS. More studies are needed to further refine this model.

Patellar Tendon Healing With Platelet-Rich Plasma A Prospective Randomized Controlled Trial

Background: The patellar tendon has limited ability to heal after harvesting its central third. Platelet-rich plasma (PRP) could improve patellar tendon healing. Hypothesis: Adding PRP to the patellar tendon harvest site would improve donor site healing and improve clinical outcome at 6 months after anterior cruciate ligament (ACL) reconstruction with a patellar tendon graft. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Twenty-seven patients were randomly divided to receive (n = 12) or not receive (n = 15) PRP in the patellar tendon harvest site during ACL reconstruction. The primary outcome was magnetic resonance imaging (MRI) assessment of patellar tendon healing (gap area) after 6 months. Secondary outcomes were questionnaires and isokinetic testing of ACL reconstruction with a patellar tendon graft comparing both groups. Results: Patellar tendon gap area was significantly smaller in the PRP group (4.9 +/- 5.3 mm(2); 95% confidence interval [CI], 1.1-8.8) than in the control group (9.4 +/- 4.4 mm(2); 95% CI, 6.6-12.2; P = .046). Visual analog scale score for pain was lower in the PRP group immediately postoperatively (3.8 +/- 1.0; 95% CI, 3.18-4.49) than in the control group (5.1 +/- 1.4; 95% CI, 4.24-5.90; P = .02). There were no differences after 6 months in questionnaire and isokinetic testing results comparing both groups. Conclusion: We showed that PRP had a positive effect on patellar tendon harvest site healing on MRI after 6 months and also reduced pain in the immediate postoperative period. Questionnaire and isokinetic testing results were not different between the groups at 6 months.

Plantar flexion force induced by amplitude-modulated tendon vibration and associated soleus V/F-waves as an evidence of a centrally-mediated mechanism contributing to extra torque generation in humans

Background: High-frequency trains of electrical stimulation applied over the human muscles can generate forces higher than would be expected by direct activation of motor axons, as evidenced by an unexpected relation between the stimuli and the evoked contractions, originating what has been called “extra forces”. This phenomenon has been thought to reflect nonlinear input/output neural properties such as plateau potential activation in motoneurons. However, more recent evidence has indicated that extra forces generated during electrical stimulation are mediated primarily, if not exclusively, by an intrinsic muscle property, and not from a central mechanism as previously thought. Given the inherent differences between electrical and vibratory stimuli, this study aimed to investigate: (a) whether the generation of vibration-induced muscle forces results in an unexpected relation between the stimuli and the evoked contractions (i.e. extra forces generation) and (b) whether these extra forces are accompanied by signs of a centrally-mediated mechanism or whether intrinsic muscle properties are the redominant mechanisms. Methods: Six subjects had their Achilles tendon stimulated by 100 Hz vibratory stimuli that linearly increased in amplitude (with a peak-to-peak displacement varying from 0 to 5 mm) for 10 seconds and then linearly decreased to zero for the next 10 seconds. As a measure of motoneuron excitability taken at different times during the vibratory stimulation, short-latency compound muscle action potentials (V/F-waves) were recorded in the soleus muscle in response to supramaximal nerve stimulation. Results: Plantar flexion torque and soleus V/F-wave amplitudes were increased in the second half of the stimulation in comparison with the first half. Conclusion: The present findings provide evidence that vibratory stimuli may trigger a centrally-mediated mechanism that contributes to the generation of extra torques. The vibration-induced increased motoneuron excitability (leading to increased torque generation) presumably activates spinal motoneurons following the size principle, which is a desirable feature for stimulation paradigms involved in rehabilitation programs and exercise training.

The effects of a water-based exercise program on strength and functionality of older adults

Objective: To analyze the effects of a water-based exercise program on peak torque (PT) and rate of torque development (RTD) during maximal voluntary ballistic isometric contractions of the lower limb muscles and the performance of a number of functional tests in the elderly. Method: Thirty-seven elderly were randomly assigned to water-based training (3 d/wk for 12 wk) or a control group. Extensor and flexor PT and RTD of the ankle, knee, and hip joints and functional tests were evaluated before and after training. Results: PT increased after training for the hip flexors (18%) and extensors (40%) and the plantar-flexor (42%) muscles in the water-based group. RTD increased after training for the hip-extensor (10%), knee-extensor (11%), and ankle plantar-flexor (27%) muscles in the water-based group. Functional tests also improved after training in the water-based group (p < .05). Conclusion: The water-based program improved PT and RTD and functional performance in the elderly.

Ultrastructural features of the myotendinous junction of the sternomastoid muscle in Wistar rats: from newborn to aging

The myotendinous junction (MTJ) is a major area for transmitting force from the skeletal muscle system and acts in joint position and stabilization. This study aimed to use transmission electron microscopy to describe the ultrastructural features of the MTJ of the sternomastoid muscle in Wistar rats from newborn to formation during adulthood and possible changes with aging. Ultrastructural features of the MTJ from the newborn group revealed pattern during development with interactions between muscle cells and extracellular matrix elements with thin folds in the sarcolemma and high cellular activity evidenced through numerous oval mitochondria groupings. The adult group had classical morphological features of the MTJ, with folds in the sarcolemma forming long projections called finger-like processes and sarcoplasmic invaginations. Sarcomeres were aligned in series, showing mitochondria near the Z line in groupings between collagen fiber bundles. The old group had altered finger-like processes, thickened in both levels of sarcoplasmic invaginations and in central connections with the lateral junctions. We conclude that the MTJ undergoes intense activity from newborn to its formation during adulthood. With increasing age, changes to the MTJ were observed in the shapes of the invaginations and finger-like processes due to hypoactivity, potentially compromising force transmission and joint stability. Microsc. Res. Tech. 75:12921296, 2012. (C) 2012 Wiley Periodicals, Inc.

Isokinetic analysis of the elbow joint in children with cerebral palsy

The joint torque is an important variable related to children with cerebral palsy. The present study analyzed kinetic parameters during elbow flexion and extension movements in healthy and cerebral palsy children. Ten healthy and 10 cerebral palsy children participated of the study. An isokinetic dynamometer was used to measure the elbow mean peak torque, mean angle peak torque, coefficient of variation and acceleration during flexion and extension movements at different angular speeds. The mean peak torque on extension movement in healthy children group was significant higher compared to the cerebral palsy group. The coefficient of variation on both flexion and extension movements was significantly higher in cerebral palsy group. However there were significantly difference on both groups compared the lowest and highest velocities. Although the results showed no difference in flexor peak torque, the acceleration is significantly lower in lowest and highest angular velocity.

Changes in FDB and soleus muscle activity after a train of stimuli during upright stance

Background: Evidence of self-sustained muscle activation following a brief electrical stimulation has been reported in the literature for certain muscles. Objectives: This report shows that the foot muscle (Flexor Digitorum Brevis - FDB) shows a self-sustained increase in muscle activity during upright stance in some subjects following a train of stimuli to the tibial nerve. Methods: Healthy subjects were requested to stand upright and surface EMG electrodes were placed on the FDB, Soleus and Tibialis Anterior muscles. After background muscle activity (BGA) acquisition, a 50 Hz train of stimuli was applied to the tibial nerve at the popliteal fossa. The root mean square values (RMS) of the BGA and the post-stimulus muscle activation were computed. Results: There was a 13.8% average increase in the FDB muscle EMG amplitude with respect to BGA after the stimulation was turned off. The corresponding post-stimulus Soleus EMG activity decreased by an average of 9.2%. We hypothesize that the sustained contraction observed in the FDB following stimulus may be evidence of persistent inward currents (PIC) generated in FDB spinal motoneurons. The post-stimulus decrease in soleus activity may have occurred due to the action of inhibitory interneurons caused by the PICs, which were triggered by the stimulus train. Conclusions: These sustained post-stimulation changes in postural muscle activity, found in different levels in different subjects, may be part of a set of possible responses that contribute to overall postural control.

Correction of Severe Ptosis with a Silicone Implant Suspensor: 22 Years of Experience

Background: Patients with severe ptosis caused by poor or absent function of the levator muscle but with good frontalis muscle excursion usually benefit from a frontalis sling procedure. This is currently carried out using organic or inorganic material to connect the upper eyelid to the frontalis muscle. Methods: The aim of this study was to evaluate retrospectively 112 patients who underwent frontalis sling procedures between 1989 and 2011 using a preformed silicone implant suspensor to correct severe ptosis. Results: The results obtained using this technique were good or fair in 95.54 percent of the cases and poor in 4.46 percent of the cases. The authors discuss the results of the study and the cases in which the procedure should be indicated and highlight the advantages of the method. Conclusion: The availability of this low-cost sterile device, together with the fact that it is ready to use, requires less invasive surgery, saves time, and is sufficiently versatile to allow adjustments to be made at any time, makes the silicone eyelid sling an attractive choice for correcting ptosis. (Plast. Reconstr. Surg. 129: 453e, 2012.)

Effect of Functional Stabilization Training on Lower Limb Biomechanics in Women

BALDON, R. D. M., D. F. M. LOBATO, L. P. CARVALHO, P. Y. L. WUN, P. R. P. SANTIAGO, and F. V. SERRAO. Effect of Functional Stabilization Training on Lower Limb Biomechanics in Women. Med. Sci. Sports Exerc., Vol. 44, No. 1, pp. 135-145, 2012. Purpose: This study aimed to verify the effects of functional stabilization training on lower limb kinematics, functional performance, and eccentric hip and knee torques. Methods: Twenty-eight women were divided into a training group (TG; n = 14), which carried out the functional stabilization training during 8 wk, and a control group (CG; n = 14), which carried out no physical training. The kinematic assessment of the lower limb was performed during a single-leg squat, and the functional performance was evaluated by way of the single-leg triple hop and the timed 6-m single-leg hop tests. The eccentric hip abductor, adductor, lateral rotator, medial rotator, and the knee flexor and extensor torques were measured using an isokinetic dynamometer. Results: After 8 wk, the TG significantly reduced the values for knee abduction (from -6.86 degrees to 1.49 degrees), pelvis depression (from -10.21 degrees to -7.86 degrees) and femur adduction (from 7.08 degrees to 5.19 degrees) as well as increasing the excursion of femur lateral rotation (from -0.55 degrees to -3.67 degrees). Similarly, the TG significantly increased the values of single-leg triple hop (from 3.52 to 3.92 m) and significantly decreased the values of timed 6-m single-leg hop tests (from 2.43 to 2.14 s). Finally, the TG significantly increased the eccentric hip abductor (from 1.31 to 1.45 N center dot m center dot kg(-1)), hip lateral rotator (from 0.75 to 0.91 N center dot m center dot kg(-1)), hip medial rotator (from 1.45 to 1.66 N center dot m center dot kg(-1)), knee flexor (from 1.43 to 1.55 N center dot m center dot kg(-1)), and knee extensor (from 3.46 to 4.40 N center dot m center dot kg(-1)) torques. Conclusions: Strengthening of the hip abductor and lateral rotator muscles associated with functional training improves dynamic lower limb alignment and increases the strength and functional performance.

Effect of the rest interval duration between contractions on muscle fatigue

Background: We aimed to investigate the effect of rest interval, between successive contractions, on muscular fatigue. Methods: Eighteen subjects performed elbow flexion and extension (30 repetitions) on an isokinetic dynamometer with 80 degrees of range of motion. The flexion velocity was 120 degrees/s, while for elbow extension we used 5 different velocities (30, 75, 120, 240, 360 degrees/s), producing 5 different rest intervals (2.89, 1.28, 0.85, 0.57 and 0.54 s). Results: We observed that when the rest interval was 2.89 s there was a reduction in fatigue. On the other hand, when the rest interval was 0.54 s the fatigue was increased. Conclusions: When the resting time was lower (0.54 s) the decline of work in the flexor muscle group was higher compared with different rest interval duration.

Muscle Atrophy and Functional Deficits of Knee Extensors and Flexors in People With Chronic Stroke

Background. Further clarification is needed with regard to the degree of atrophy in individual muscle groups and its possible relationship to joint torque deficit poststroke. Objective. The purpose of this study was to investigate quadriceps and hamstring muscle volume and strength deficits of the knee extensors and flexors in people with chronic hemiparesis compared with a control group. Design. This was a cross-sectional study. Methods. Thirteen individuals with hemiparesis due to chronic stroke (hemiparetic group) and 13 individuals who were healthy (control group) participated in this study. Motor function, quadriceps and hamstring muscle volume, and maximal concentric and eccentric contractions of the knee extensors and flexors were assessed. Results. Only the quadriceps muscle of the paretic limb showed reduced muscle volume (24%) compared with the contralateral (nonparetic) limb. There were no differences in muscle volume between the hemiparetic and control groups. The peak torque of the paretic-limb knee extensors and flexors was reduced in both contraction modes and velocities compared with the nonparetic limb (36%-67%) and with the control group (49%-75%). The nonparetic limb also showed decreased extensor and flexor peak torque compared with the control group (17%-23%). Power showed similar deficits in strength (12%-78%). There were significant correlations between motor function and strength deficits (.54-.67). Limitations. Magnetic resonance imaging coil length did not allow measurement of the proximal region of the thigh. Conclusions. There were different responses between quadriceps and hamstring muscle volumes in the paretic limb that had quadriceps muscle atrophy only. However, both paretic and nonparetic limbs showed knee extensor and flexor torque and power reduction.

Exercise training program based on minimum weekly frequencies: effects on blood pressure and physical fitness in elderly hypertensive patients

Background: Exercise training (ET) can reduce blood pressure (BP) and prevent functional disability. However, the effects of low volumes of training have been poorly studied, especially in elderly hypertensive patients. Objectives: To investigate the effects of a multi-component ET program (aerobic training, strength, flexibility, and balance) on BP, physical fitness, and functional ability of elderly hypertensive patients. Methods: Thirty-six elderly hypertensive patients with optimal clinical treatment underwent a multi-component ET program: two 60-minute sessions a week for 12 weeks at a Basic Health Unit. Results: Compared to pre-training values, systolic and diastolic BP were reduced by 3.6% and 1.2%, respectively (p < 0.001), body mass index was reduced by 1.1% (p < 0.001), and peripheral blood glucose was reduced by 2.5% (p= 0.002). There were improvements in all physical fitness domains: muscle strength (chair-stand test and elbow flexor test; p < 0.001), static balance test (unipedal stance test; p < 0.029), aerobic capacity (stationary gait test; p < 0.001), except for flexibility (sit and reach test). Moreover, there was a reduction in the time required to perform two functional ability tests: "put on sock" and "sit down, stand up, and move around the house" (p < 0.001). Conclusions: Lower volumes of ET improved BP, metabolic parameters, and physical fitness and reflected in the functional ability of elderly hypertensive patients. Trial Registration RBR-2xgjh3.

Low-level laser therapy in collagenase-induced Achilles tendinitis in rats: Analyses of biochemical and biomechanical aspects

NSAIDs are widely prescribed and used over the years to treat tendon injuries despite its well-known long-term side effects. In the last years several animal and human trials have shown that low-level laser therapy (LLLT) presents modulatory effects on inflammatory markers, however the mechanisms involved are not fully understood. The aim of this study was to evaluate the short-term effects of LLLT or sodium diclofenac treatments on biochemical markers and biomechanical properties of inflamed Achilles tendons. Wistar rats Achilles tendons (n?=?6/group) were injected with saline (control) or collagenase at peritendinous area of Achilles tendons. After 1?h animals were treated with two different doses of LLLT (810?nm, 1 and 3?J) at the sites of the injections, or with intramuscular sodium diclofenac. Regarding biochemical analyses, LLLT significantly decreased (p?<?0.05) COX-2, TNF-a, MMP-3, MMP-9, and MMP-13 gene expression, as well as prostaglandin E2 (PGE2) production when compared to collagenase group. Interestingly, diclofenac treatment only decreased PGE2 levels. Biomechanical properties were preserved in the laser-treated groups when compared to collagenase and diclofenac groups. We conclude that LLLT was able to reduce tendon inflammation and to preserve tendon resistance and elasticity. (c) 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:19451951, 2012

Distribuição do nervo ibular comum em fetos de equinos e descrição anatômica de pontos para bloqueio anestésico

Analisou-se a distribuição do nervo fibular comum em 30 fetos de equinos, sem raça definida, provenientes do acervo do Laboratório de Anatomia Animal da Faculdade de Medicina Veterinária da Universidade Federal de Uberlândia, que foram injetados e conservados em solução aquosa de formaldeído a 10%. Contatou-se que o referido nervo deriva do isquiático, divide-se em nervos fibulares superficial e profundo, distribuindo-se para os músculos extensores lateral e longo do dedo, fibular terceiro e tibial cranial. Traçando-se uma linha imaginária na região médio-lateral da tuberosidade do osso tíbia, o nervo fibular comum pode ser bloqueado em sua parte proximal, no terço caudal, entre o tendão de inserção do músculo bíceps femoral e a face lateral do músculo gastrocnêmio lateral (terço médio); e o nervo fibular profundo, na parte proximal da tíbia, crânio-distalmente ao fibular comum. O bloqueio do nervo fibular superficial pode ser realizado em duas regiões da tíbia: na proximal, considerando-se a linha imaginária, distalmente ao ponto citado para o fibular comum e caudalmente ao descrito para o fibular profundo; e na distal, na face lateral da articulação tíbio-társica, entre os tendões de inserção dos músculos extensores lateral e longo do dedo.