Gastrocnemius muscle architecture in distance runners with and without Achilles tendinopathy

Background: Achilles tendinopathy is a common condition amongst distance runners due to the cumulative repetitive overload of the tendon. Gastrocnemius weakness and inflexibility can predispose to this condition. Thesepredisposing functional deficits could have architectural underpinnings, but the gastrocnemius architecture of distance runners with Achilles tendinopathy has not been previously described or compared to the architecture of healthy distance runners. Objectives: We aimed to investigate the differences in gastrocnemius architecture between distance runners withAchilles tendinopathy and uninjured counterparts. Methods: Twenty distance runners (10 with Achilles tendinopathy; 10 uninjured) were recruited to this study. Ultrasound measurement of the gastrocnemius muscle architecture (pennation angle; fascicle length; muscle thickness; muscle belly length; muscle volume; physiological cross-sectional area) was performed. Results: Gastrocnemius Medial Head (GM) fascicle length was significantly greater (p = 0.02), whilst the physiological cross-sectional area (PCSA) was significantly less (p = 0.01) in the case group. Gastrocnemius Lateral Head (GL) pennation angle (p = 0.01) and PCSA (p = 0.01) were significantly lower, whilst fascicle length was significantly greater (p = 0.01) in the case group. There were no significant between-group differences in GM and GL muscle thickness, muscle belly length, or muscle volume. Conclusion: Components of gastrocnemius architecture differ significantly between distance runners with Achillestendinopathy and uninjured controls in our study sample. This study cannot infer whether these results are secondary or predisposing to the condition. Further longitudinal investigation is required to explore these relationships further

What Is New about the Semimembranosus Distal Tendon? Ultrasound, Anatomical, and Histological Study with Clinical and Therapeutic Application

The semimembranosus muscle inserts into several tendons that are associated with some pathologies. Although ultrasound is useful for studying, diagnosing, and managing these pathologies, the correct interpretation of any images requires a clear knowledge of the related anatomical structures and the inter-related functions. We studied 38 cryopreserved non-paired knees from adult anatomical specimens and 4 non-paired knees from 29 to 38-week-old fetuses. The semimembranosus muscle and its tendons were located, observed, and injected under ultrasound guidance. The macroscopic anatomy was studied using dissection and anatomical cuts and the tendons were analyzed histologically. Measurements of muscle were taken 10 cm from the medial epicondyle and just before the tendon divided. The ultrasound facilitated the identification of the different divisions of the tendon of semimembranosus muscle and the rotation of the muscle and tendon from medial to posterior. An anatomical study confirmed this rotation and revealed an average width, thickness, and diameter of 38.29 mm, 14.36 mm, and 112.64 mm, respectively. Important relationships were observed between the divisions of the main tendons and the medial collateral ligament, the posterior side of the knee and popliteus muscle. This information can help to explain knee pathologies and facilitate rehabilitation after surgery

A novel approach to sonographic examination in a patient with a calf muscle tear: a case report

© 2009 Chen et al; licensee Cases Network Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Rupture of the medial head of the gastrocnemius muscle in late-career and former elite jūdōka: a case report

Introduction. In 1883 Powell in The Lancet for the first time described a clinical condition incurred during lawn tennis, and which involved a calf injury that most commonly resulted from sprinting acceleration or a sudden change in running direction, and which hence became known under the name “tennis leg”. In the present case report we describe for the first time how, a similar injury arises from a very different way of moving that may occur during the practice of jūdō. Case presentation. A 52-year-old male former elite jūdō athlete of African-American ethnicity, during the entry for performing a jūdō shoulder throw, upon pushing off with the front part of his right foot while making an inward turning motion and simultaneously stretching his right knee, heard a snapping sound in the mid-portion of his right calf accompanied by a sudden sharp pain and immediate loss of functionality. Ultrasonography and clinical findings were consistent with a partial rupture of the distal part of the medial head of the right gastrocnemius muscle. Differential diagnosis. Achilles tendon rupture, arterial aneurysm, Baker’s cyst, deep venous thrombosis, ischemic necrosis, tendon strain or rupture of the plantaris or soleus muscles, tendon strain or rupture. Treatment. Proper acute care (P.R.I.C.E.-principle [Protection-Rest-Ice-Compression-Elevation]) and rehabilitation were adhered to, which contributes to excellent prognosis of partial gastrocnemius ruptures. Uniqueness of the study. “Tennis leg” as previously described has not been associated with practicing jūdō. Conclusion. Simultaneous active plantar flexion or dorsiflexion of the foot and extension of the knee, as may occur during entry for some standing jūdō throws, puts the gastrocnemius muscle at risk for rupture. Predisposing factors are its high density in type-2 fast-twitch muscle fibers, reduced neoangiogenesis, increased nonimmuno-hematopoietic cell content, muscle fatigue, adipositas athletica, metabolic syndrome, male gender, and age-related sarcopenia

Gastrocnemius muscle herniation as a rare differential diagnosis of ankle sprain: case report and review of the literature

BACKGROUND: Muscle herniation of the leg is a rare clinical entity. Yet, knowing this condition is necessary to avoid misdiagnosis and delayed treatment. In the extremities, muscle herniation most commonly occurs as a result of an acquired fascial defect, often due to trauma. Different treatment options for symptomatic extremity muscle herniation in the extremities, including conservative treatment, fasciotomy and mesh repair have been described. CASE PRESENTATION: We present the case of a patient who presented with prolonged symptoms after an ankle sprain. The clinical picture showed a fascial insufficiency with muscle bulging under tension. Ultrasound and MRI imaging confirmed the diagnosis of muscle hernia of the medial gastrocnemius on the right leg. Conservative treatment did not lead to success. Therefore, the fascial defect was treated surgically by repairing the muscle herniation using a synthetic vicryl propylene patch. CONCLUSIONS: Muscle hernias should be taken into consideration as a rare differential diagnosis whenever patients present with persisting pain or soft tissue swelling after ankle sprain. Diagnosis is mainly based on clinical aspect and physical examination, but can be confirmed by radiologic imaging techniques, including (dynamic) ultrasound and MRI. If conservative treatment fails, we recommend the closure with mesh patches for large fascial defects

The plantaris muscle — rare relations to the neurovascular bundle in the popliteal fossa

The plantaris muscle is characterised by morphological variability, both for origin and insertion, and may sometimes be absent. Its strength allows the ligament to be used for reconstruction of other tendons and ligaments. This report presents the rare placements and course of the plantaris muscle in relation to the neurovascular bundle. In this case, the hypertrophy of this muscle might cause pressure on the tibial nerve and produce symptoms similar to sciatica

An evaluation of gastrocnemius muscle structure and function in endurance runners and low physical activity individuals

Includes abstract.Includes bibliographical references.Distance running has become increasingly popular in recreational runners. The gastrocnemius is the main muscle used for propulsion in running, and may be at risk for injury due to its morphology. In previous studies, changes in the morphology and architecture of the gastrocnemius muscle have been evident following training, but it is unclear whether these changes are related to training or youth. Previous studies of runners have shown a decrease in gastrocnemius and soleus flexibility, as well as changes in the fascicle length and pennation angle. Gastrocnemius volume has not been compared in low physical activity and active participants. Physiological cross sectional area, based on volume and fascicle length measurements may also provide valuable information about the muscle’s ability to produce force. Ultrasound may be a useful tool in assessing potential training adaptations in the morphology and architecture of the gastrocnemius muscle. The aim of this cross-sectional descriptive study was to assess the differences in architecture and function of the gastrocnemius in endurance runners compared to low physical activity participants. (a) To assess differences in calf function and flexibility between endurance runners and low physical activity individuals, and between male and female participants; (b) To determine differences in gastrocnemius muscle architecture and composition between endurance runners versus low physical activity individuals, and between males and females; and (c) To determine whether there are any relationships between training factors and the structure and function of the gastrocnemius muscle. Thirty participants between 20 and 45 years old were recruited for this study and allocated to groups based on their level of physical activity. The low physical activity group (n = 14) were not participating in any regular physical activity, while the endurance running group (n = 16) were running a minimum of 40 km.wk-1, and had participated in at least one full marathon (42.2 km) in the previous six months. All participants completed informed consent, a physical activity and training questionnaire, and a Physical Activity Readiness Questionnaire (PAR-Q) at the first session. The first session also included body composition measurements; ultrasound imaging to measure gastrocnemius length, thickness, fascicle length, pennation angle and volume; and familiarisation with all physical tests. Physical tests were conducted in the second session, including gastrocnemius and soleus flexibility, calf raise endurance and vertical jump height to assess the function of the components of the triceps surae. There were no significant differences between low physical activity and running groups for gastrocnemius thickness, fascicle length, pennation angle and gastrocnemius length. Gastrocnemius volume (p = 0.02) and physiological cross sectional area (p = 0.01) were significantly greater in the running group compared to the low physical activity group. There were no significant differences between low physical activity and running groups in flexibility or vertical jump height, although male participants had significantly decreased gastrocnemius muscle flexibility (p = 0.046) and significantly greater vertical jump heights (p = 0.01) than females. Calf raise endurance was significantly greater in the running group than in the low physical activity group (p = 0.03). Endurance running leads to specific adaptations in participants in both structure and function. While ultrasound appears to be a reliable measure for assessing architectural components of the gastrocnemius muscle in both active and inactive populations, further cadaver studies may provide valuable information on muscle architecture

An Outpatient Physical Therapy Non-Operative Management and Intervention for an Older, Athletic, Professional, Caucasian Male Patient with an Acute Gastrocnemius Medialis and Lateralis Muscle Rupture

Description: The gastrocnemius muscle is a two joint muscle originating on the femur and inserting into the calcaneus through the Achilles tendon. The gastrocnemius spans the knee and ankle joint providing important stabilization and movement functions in walking, running, and jumping activities. Rupture of the Achilles tendon is one of the most common tendinous injuries. Non-operative, conservative treatment of the acute Achilles tendon rupture demonstrates comparable results to surgical intervention. Non-operative management promotes patient tolerance, low cost, and positive clinical outcomes. Previous studies have supported the concept of functional bracing as a conservative, alternate treatment for an acutely ruptured Achilles tendon. Physical therapy modalities and exercise interventions are a common occurrence after Achilles tendon injuries. The purpose of this case report is to describe the use and outcome of non-operative treatment including functional bracing, physical therapy modalities, and exercise interventions after an acute gastrocnemius medialis and lateralis muscle rupture in one patient. Procedures/Methods: The proposed study will utilize the physical therapy examination, evaluation, and intervention as a representative case report to augment the knowledge currently available for the topic of gastrocnemius and soleus ruptures. Evidence based research will be utilized to identify current best practices in the area of Achilles tendon and gastrocnemius rupture and repair. Results: Through the application of evidence based examination and intervention, the results of this project should improve client outcomes for physical therapy services. This case report may stimulate future research comparing non-operative management and intervention of acute gastrocnemius medialis and lateralis muscle rupture with operative management and intervention

Estimation of Absolute States of Human Skeletal Muscle via Standard B-Mode Ultrasound Imaging and Deep Convolutional Neural Networks

Objective: To test automated in vivo estimation of active and passive skeletal muscle states using ultrasonic imaging. Background: Current technology (electromyography, dynamometry, shear wave imaging) provides no general, non-invasive method for online estimation of skeletal muscle states. Ultrasound (US) allows non-invasive imaging of muscle, yet current computational approaches have never achieved simultaneous extraction nor generalisation of independently varying, active and passive states. We use deep learning to investigate the generalizable content of 2D US muscle images. Method: US data synchronized with electromyography of the calf muscles, with measures of joint moment/angle were recorded from 32 healthy participants (7 female, ages: 27.5, 19-65). We extracted a region of interest of medial gastrocnemius and soleus using our prior developed accurate segmentation algorithm. From the segmented images, a deep convolutional neural network was trained to predict three absolute, driftfree, components of the neurobiomechanical state (activity, joint angle, joint moment) during experimentally designed, simultaneous, independent variation of passive (joint angle) and active (electromyography) inputs. Results: For all 32 held-out participants (16-fold cross-validation) the ankle joint angle, electromyography, and joint moment were estimated to accuracy 55±8%, 57±11%, and 46±9% respectively. Significance: With 2D US imaging, deep neural networks can encode in generalizable form, the activitylength-tension state relationship of these muscles. Observation only, low power, 2D US imaging can provide a new category of technology for non-invasive estimation of neural output, length and tension in skeletal muscle. This proof of principle has value for personalised muscle assessment in pain, injury, neurological conditions, neuropathies, myopathies and ageing

The Effect of Static Stretching on Proprioception, Pennation Angle, and Muscle Power Production

With widespread use of pre-exercise stretching methods across sport and exercise, recent studies have questioned the effectiveness of such methods (Kay & Blazevich 2012; Cramer et al., 2005; Curry, Chengkalath, Crouch, Romance, & Manns, 2009). The purpose of this study was to examine how the relationship between pennation angle, proprioception, and muscle power are influenced by a static stretching protocol. Participants (n = 17) from a southeastern university in the United States consented to participate and were divided into an experimental group (n = 12) and control group (n = 5). The experimental group engaged in static stretched by placing the right foot on an incline board and maximally dorsiflexing the ankle joint while keeping the bottom of their foot flush with the board’s surface and the knee fully extended. The control group remained seated for the same amount of time and did not engage in stretching. Both groups were measured for vertical jump using the Vertec force plate, electrical activity of the gastrocnemius via the Terason ultrasound machine, and proprioception of the ankle joint via the Biodex 2 dynamometer pre- and post- stretching and control protocols. Results indicated that static stretching resulted in a decrease in muscle power without change of proprioception or electrical-mechanical delay while accompanied by an increase in pennation angle. The increase in pennation angle may the reason why static stretch resulted in a reduction in muscle power. The results are discussed in regard to previous research and future practical application