Head Of Gastrocnemius Muscle Research Articles

Posterior popliteal fossa S-shaped incision with double-window approach in treating posterior column of tibial plateau fractures

To evaluate the effectiveness and safty of posterior popliteal fossa S-shaped incision with double-window approach for the treatment of posterior column of tibial plateau fractures. A retrospective analysis was made on the clinical data of 13 patients with complex tibial plateau fractures involving both posteromedial and posterolateral columns between May 2015 and July 2017. There were 9 males and 4 females, aged 33-64 years (mean, 46.5 years). The causes of injury included traffic accident in 5 cases, falling from height in 2 cases, falling from electric bicycle in 4 cases, and falling because of skiing in 2 cases. The preoperative range of motion of the affected knees was (35.1±9.2)°. The time from injury to surgery was 7-19 days (mean, 13.3 days). All patients underwent a posterior popliteal fossa S-shaped incision through the window of medial heads of gastrocnemius muscle (medial window) and the window between medial and lateral head of gastrocnemius muscle (popliteal fossa window) approaches. After a good visual control of fracture reduction, both posteromedial and posterolateral columns of tibial plateau fractures were fixed with buttress plate respectively. Bone union, limb alignment, articular surface, and range of motion were estimated after operation. The American Hospital for Special Surgery (HSS) score was used to evaluate functional outcomes of knees. After operation, 1 patient had fat liquefaction and dehiscence of incision, which healed after expanding the wound; the other patients' incisions healed by first intention, and no vascular or nerve injury occurred during operation. All the 13 patients were followed up 12-18 months (mean, 16 months). The X-ray films showed that all patients obtained good fracture unions, the fracture healing time was 14-22 weeks (mean, 18 weeks). At 12 months after operation, the articular surface was smooth without collapse, and the knee range of motion was (109.5±13.6)°, showing significant difference when compared with preoperative value ( t=18.879, P=0.000). No complication of infection, re-displacement of fracture, or secondary varus/valgus deformity was observed during follow-up. The HSS score was 82-96 (mean, 89.6) at 12 months after operation, with the result of excellent in 10 cases and good in 3 cases. The posterior column fracture of tibial plateau involving both posteromedial and posterolateral columns treated by double-window approach through posterior popliteal fossa S-shaped incision is safe and effective, with satisfactory results and good recovery of knee joint function.

The ultrasonographic measurement of muscle thickness in sarcopenia. A prediction study

Sarcopenia is a common disease in the elderly. Although extensive research has been conducted on muscle mass and quality assessment tools, there are still certain drawbacks preventing their universal use. The aim of this study was the evaluation of the thickness of head, neck, upper and lower limb muscles measured with ultrasonography, as a potential predictory tool in sarcopenia. Prediction study. The Outpatient Sarcopenia Clinic of the Rehabilitation Department of the University Hospital of Patras. Ninety-four individuals (27 men and 67 women) with a mean age of 75.6 years (SD=6.6), referred for sarcopenia screening, participated in this study. The muscle thickness was measured with transverse and longitudinal ultrasound scans bilaterally. The thickness of the geniohyoid and medial head of gastrocnemius muscle in all ultrasound sections, and the thickness of the rectus femoris and vastus intermedius muscle, in specific sections, was found to be significantly decreased in patients with sarcopenia (P<0.05). The Receiver Operating Characteristic (ROC) curve analysis of the ultrasound muscle thickness measurements resulted in a significant association with sarcopenia. In the case of the geniohyoid muscle, the measured area under the ROC curve was found to be the highest (0.79). The optimal cut-off for the prediction of sarcopenia from the geniohyoid muscle was 0.65 cm with sensitivity equal to 75.0% and specificity equal to 66.7%. The results of this study have shown that the thickness of the neck and lower limb muscles measured ultrasonographically can be utilized in the prediction of sarcopenia with high sensitivity and specificity. The prevalence of sarcopenia in the geriatric population and the rehabilitation wards is reported to be high. Therefore, an easy, fast, low cost and with no risk, widely available method such as ultrasonography could be an extremely valuable tool for the screening and follow-up of sarcopenia.

Cerebellar Transcranial Magnetic Stimulation Disrupts Vestibular Reflexes in Standing Balance

Despite its seemingly effortless execution, standing balance is a complex task maintained by the integration of sensory feedback from visual, somatosensory (muscle, skin, joint receptors), and vestibular (inner ear) systems. The vestibular system provides feedback about head acceleration and can be manipulated experimentally by passing an electrical current percutaneously through the mastoid processes. The cerebellum plays an important role in standing balance by integrating sensory feedback to refine activity in postural muscles. A recent study has shown that experimentally depressing cerebellar activity with repetitive transcranial magnetic stimulation can influence postural sway and muscle reflex responses following electrical vestibular stimulation. The aim of this study was to investigate the impact of acute cerebellar stimulation on vestibular muscle reflex responses in different head positions during standing balance. We applied a novel combination of stochastic electrical vestibular stimulation (SVS, ±2.5 mA, 0–20 Hz) and single‐pulse cerebellum transcranial magnetic stimulation (TMS, 60% maximum stimulator output) on fifteen healthy adults (6 males, 9 females; 21–32 years old) in two head positions: head forward and head right. Muscle reflexes were recorded bilaterally with surface electromyography (EMG) from lower leg (soleus and medial gastrocnemius) and neck (sternocleidomastoid) muscles. Time‐based cumulant density and frequency‐based coherence analyses were used to evaluate the relationship between the SVS and evoked EMG responses one second before (Pre) and one second after (Post) cerebellar TMS. 50 TMS pulses were delivered per head position. Preliminary analysis performed on left medial gastrocnemius (LMG) head right data indicated a significant reduction in the short latency (SL, P = 0.0377) and medium latency (ML, P &lt; 0.0001) reflexes following cerebellar TMS (Fig. 1). In addition, a significant drop in the coherence between the SVS and LMG Pre to Post was found using a difference of coherence test. These findings support the cerebellum to be an important center for the integration of vestibular feedback for the control of standing balance.Support or Funding InformationMount Royal University Faculty of Science and TechnologyFigure 1

Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain

The objectives of this study were (1) to investigate the passive stiffness of the medial gastrocnemius (MG) and lateral gastrocnemius (LG) in patients with and without plantar fasciitis (PF), (2) to explore the correlation between gastrocnemius stiffness and plantar fascia thickness (PFT) as well as the intensity of pain in patients with PF, (3) to detect optimal cut-off points for stiffness of the MG and LG for identifying patients with PF. Forty patients (mean age = 51.1 years ± 12.9) participated in this study. The elastic properties of the MG and LG were quantified using shear wave elastography ultrasound. The thickness of the plantar fascia was measured by B-mode imaging. The intensity of pain was assessed using a visual analogue scale. The results showed that when the ankle was in the relaxed position, patients with PF had increased passive stiffness in the MG (P < 0.05) but not in the LG. Significant correlations were found between pain and the stiffness of the MG (middle, distal; all P-values < 0.05) and no correlation was observed between pain and PFT (P = 0.416). The initial cut-off point for the stiffness of the MG was 29.08 kPa when the ankle was in the relaxed position. The findings from the present study show that an increase in muscle stiffness is not the same in the individual muscles of the gastrocnemius muscle. Traditional treatment of the whole gastrocnemius muscle might not be targeted at the tight muscle.

Variations in the branching pattern of the tibial nerve in the posterior compartment of the leg

Background: Tibial nerve is the largest branch of sciatic nerve. It innervates muscles of the posterior compartment of the leg. Knowledge of the variations in motor branching pattern may help the surgeons when certain procedures are done for calf reduction and also for spastic equinus foot where selective neurectomy is required. It is also required for anesthetists for inducing neurolytic blocks. The aim of the present study was to study the variations in its branching pattern of the tibial nerve in the posterior compartment of the leg. Materials and Methods: The study was done by dissecting forty formalin-fixed lower limbs from twenty adult human cadavers. The origin of tibial nerve, variations, branching pattern, number of muscular branches and termination of the tibial nerve were studied. The level of origin of these nerves was taken in relation to the apex of head of fibula. Results: 57.5% showed that the origin was <12 cm and 42.5% were between 12 and 24 cm above the level of apex of head of fibula. The flexor hallucis longus received one branch in 70% and two branches in 30% of the specimens. Forty percent of the branches showed two or three divisions. The flexor digitorum longus received one branch in 95% and two branches in 5% of the specimens. Eighty percent of the branches of the muscle showed 2–4 divisions. 82.5% of nerve to soleus muscle had one branch and 17.5% had two branches. In 17.5% of the specimens, nerve to soleus originated from the nerve to the lateral head of gastrocnemius. Thirty percent of the branches showed 2–3 divisions. All specimens had one branch which supplied the tibialis posterior muscle and 47.5% of the branches showed 2–3 divisions. In 77.5% of the specimens, the termination occurred above the malleolar calcaneal axis. Conclusion: The flexor hallucis longus, flexor digitorum longus, and soleus muscle had one or two branches from tibial nerve. Single branch innervates tibialis posterior. Nerves to flexor hallucis longus, tibialis posterior, and the soleus had up to three divisions and nerve to flexor digitorum longus had up to four divisions.

Study on the Recognition of Exercise Intensity and Fatigue on Runners Based on Subjective and Objective Information.

A running exhaustion experiment was used to explore the correlations between the time-frequency domain indexes extracted from the surface electromyography (EMG) signals of targeted muscles, heart rate and exercise intensity, and subjective fatigue. The study made further inquiry into the feasibility of reflecting and evaluating the exercise intensity and fatigue effectively during running using physiological indexes, thus providing individualized guidance for running fitness. Twelve healthy men participated in a running exhaustion experiment with an incremental and constant load. The percentage of heart rate reserve (%HRR), mean power frequency (MPF) and root mean square (RMS) from surface EMG (sEMG) signals of the rectus femoris (RF), biceps femoris (BF), tibialis anterior muscle (TA), and the lateral head of gastrocnemius (GAL) were obtained in real-time. The data were processed and analyzed with the rating of perceived exertion (RPE) scale. The experimental results show that the MPF on all the muscles increased with time, but there was no significant correlation between MPF and RPE in both experiments. Additionally, there was no significant correlation between RMS and RPE of GAL and BF, but there was a negative correlation between RMS and RPE of RF. The correlation coefficient was lower in the constant load mode, with the value of only −0.301. The correlation between RMS and RPE of TA was opposite in both experiments. There was a significant linear correlation between %HRR and exercise intensity (r = 0.943). In the experiment, %HRR was significantly correlated with subjective exercise fatigue (r = 0.954). Based on the above results, the MPF and RMS indicators on the four targeted muscles could not conclusively identify fatigue of lower extremities during running. The %HRR could be used to identify exercise intensity and human fatigue during running and could be used as an indicator of recognizing fatigue and exercise intensity in runners.

Regional Elastic Properties of the Achilles Tendon Is Heterogeneously Influenced by Individual Muscle of the Gastrocnemius.

Background Anatomical studies and the mechanical property studies showed that there is a strong correlation between Achilles tendon (AT) elasticity and individual gastrocnemius muscle (the medial head of gastrocnemius (MG) and the lateral head of gastrocnemius (LG)) elasticity. Limited ankle dorsiflexion range of motion has been correlated with decreased flexibility of the MG/LG/AT complex. However, no studies have been conducted to examine the exact correlation between the Achilles tendon and the individual muscle of the gastrocnemius. Purposes The purposes of the present study were (1) to evaluate intra- and interoperator reliabilities of elastic property measurements in the gastrocnemius muscle-Achilles tendon complex by using the shear wave elastography (SWE) and (2) to examine the correlation between the regional elastic properties of the AT and the individual muscle of the gastrocnemius. Methods Twenty healthy subjects (mean age: 22.50 (3.02) years) were recruited in this study. The elastic properties of the AT and the individual muscle of the gastrocnemius were quantified using the SWE. Findings The SWE has comparatively high reliability in quantifying the elastic properties of the muscle-tendon range from good to excellent. The intraoperator ICC of the gastrocnemius muscle-Achilles tendon complex was 0.77 to 0.95, while the interoperator ICC was 0.76 to 0.94. The minimal detectable change (MDC) of the muscle was 1.72 kPa, while the AT was 32.90 kPa. A significant correlation was found between the elastic modulus of AT and the elastic modulus of the MG (r = 0.668 and p = 0.001 at the relaxing position and r = 0.481 and p = 0.032 at the neutral position). Conclusions The SWE has the potential to assess localized changes in muscle-tendon elastic properties, provide more intuitive relations between elastic properties of the muscle tendon and function, and evaluate the therapeutic effect of the muscle tendon. A significant correlation between the AT and the MG was found, and it may provide a new treatment idea (targeted to the tight muscle heads) for the clinical setting to treat subjects with AT disorders.

Nerve dysfunction leads to muscle morphological abnormalities in chronic inflammatory demyelinating polyneuropathy assessed by MRI.

Neuropathic features of chronic inflammatory demyelinating polyneuropathy (CIDP) have been well documented, however very little is known about the implication of this neuropathy on skeletal muscle, and whether nerve lesions in CIDP lead to uniform disruptions in skeletal muscles. In this study, we assessed the triceps surae complex, using magnetic resonance imaging (MRI) in a group (n = 10) of CIDP patients compared with a healthy age-matched control group (n = 9). MRI (T1 and T2) of the leg musculature as well as plantar flexion strength measurements were obtained from both groups. CIDP patients compared with controls had ∼28% lower plantar flexion strength and ∼19% less total muscle volume (T1) of the triceps surae. When strength was normalized to fat corrected triceps surae volume CIDP patients were ∼30% weaker than controls. Relaxation times from the T2 scans were significantly longer in CIDP with the soleus, medial head of gastrocnemius and lateral head of gastrocnemius showing ∼37%, ∼38% and ∼26% longer relaxation times, respectively. CIDP patients were significantly weaker compared to controls and despite normalizing strength to total triceps surae contractile tissue volume this difference remained. CIDP patients had significantly longer T2 times, reflecting increased noncontractile tissue infiltration. These results indicate reduced muscle quantity and quality as a result of alterations in axonal function. Furthermore, when present study results are considered together with a prior report on the anterior compartment (Gilmore et al. 2016, Muscle Nerve 3:413-420), it is clear that both anterior and posterior leg compartments are affected similarly in CIDP despite different terminal nerve innervation and functional properties. Clin. Anat. 32:77-84, 2019. © 2019 Wiley Periodicals, Inc.

Measurement of the shear modulus in thin-layered tissues using numerical simulations and shear wave elastography

Measurement of mechanical properties of thin-layered tissues has broad applications in the diagnosis of several pathologies. Ultrasound shear wave elastography (SWE) measures the shear wave speed as a means of estimating the mechanical properties of tissues. However, the wave speed in thin-layered tissues is affected by their thickness and the properties of surrounding tissues. The objective of this study is to introduce a method that combines numerical simulations and SWE measurements to provide a more accurate calculation of shear modulus in layered tissues. In the proposed method, the spatial distribution of the acoustic radiation force (ARF) emitted by the transducer was first computed. The ARF was then used as input for simulating the guided wave propagation in the thin layer with its surroundings. The simulations were repeated for several values of the shear modulus of the layer to obtain the corresponding simulated wave speed. By comparing the measured and simulated wave speeds, a more accurate (corrected) shear modulus can be obtained. The proposed method was validated using experiments in agarose gels. In-vivo SWE measurements were also performed for the fascia of the tibialis anterior (TA) muscle and the aponeurosis of musculotendinous junction (MTJ) in medial gastrocnemius (MG) head in a group of healthy individuals. The simulated and measured wave speed in gel constructs were in good agreement with a maximum error of 7.22%. The average of measured wave speed of fascia and aponeurosis was 3.90 ± 0.16 m/s and 2.33 ± 0.60 m/s, while the corresponding corrected shear modulus was 95.63 ± 17.89 kPa and 6.36 ± 8.98 kPa, respectively. Thickness had a substantial effect on the wave speed in thin-layered tissues with decreasing speed for thinner tissues. The SWE-based simulation method presented in this study has the potential of enhancing clinical assessment for several musculoskeletal conditions involving thin-layered tissues.

Proximal Ultrasound-Guided Gastrocnemius Recession: A New Ultra-Minimally Invasive Surgical Technique

Selective proximal recession of the medial gastrocnemius head has clear advantages over other approaches and can be performed as a single or combined open procedure for many indications. The purpose of this study was to evaluate the safety and efficacy of a new technique based on ultrasound-guided ultraminimally invasive proximal gastrocnemius recession. We performed a pilot study with 16 cadavers to ensure that the technique was effective and safe; we then prospectively performed gastrocnemius recession in 12 patients (23 cases) with gastrocnemius contracture associated with other indications. We evaluated pre- and postprocedure dorsiflexion, clinical outcomes (based on the visual analog scale and American Orthopedic Foot and Ankle Society scores), and potential complications. We achieved effective release of the proximal medial gastrocnemius tendon in all cases, with no damage to other tissue. Ankle dorsiflexion increased 12° (range 6° to 18°) (p = .05) and was maintained throughout follow-up. The mean preoperative visual analog scale score was 7 (range 5 to 9), which improved to 1 (range 0 to 2) (p = .01). The American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score improved from a mean of 25 (range 20 to 40) to 85 (range 80 to 100) at 6 months and 90 at 12 months (p = .01). No major complications were observed. We considered the technique to be safe and effective for ultrasound-guided ultraminimally invasive proximal-medial gastrocnemius recession using a 1-mm incision in vivo. This novel technique is an alternative to open techniques, with encouraging results and with the potential advantages of reducing pain and obviating lower limb ischemia and deep anesthesia, thus decreasing complications and contraindications and accelerating recovery, although further studies are required.

Force-Temporal Characteristics of EEG-EMG Coherence during Isometric Contraction of Lateral Head of Gastrocnemius Muscle.

Coherence between an electroencephalogram (EEG) and an electromyogram (EMG) of the soleus (SOL) muscle during an isometric contraction is observed in the beta-band (15 to 35 Hz) regardless of the contraction force. However, the dynamics on how a variation in coherence occurs over time in the head of the gastrocnemius (GLH) muscle, which is also known to have the same role as the soleus muscle, have yet to be considered. In this study, we focused on GLH and measured an EEG and EMG taken of the GLH muscle when executing an isometric contraction through the dorsiflexion of the right ankle joint for a 1-min period. Moreover, we investigated changes in the EEG-EMG coherence based on the contraction force and elapsed time. As a result, in most subjects, the peak coherence during a weak contraction force was continuously observed in the β-band, whereas the peak coherence during a strong contraction force was observed in the γ-band (35 to 60 Hz) for only the first 12 s. In addition, no significant coherence was observed. Therefore, it was suggested that muscle fatigue induced by a strong contraction force affects the peak coherence. Meanwhile, the inconsistencies observed between the properties of the peak coherence and SOL might be due to the differences in muscle composition.

Healing Process of Gastrocnemius Muscle Injury on Ultrasonography Using B-Mode Imaging, Power Doppler Imaging, and Shear Wave Elastography.

Muscle injury often occurs in sports activity. To avoid reinjury, it is important to determine the appropriate period until return to play after injury. The purpose of this study was to evaluate characteristics of the healing process for gastrocnemius muscle injury by B-mode imaging, power Doppler (PD) imaging, and shear wave elastography (SWE). Twenty patients with acute calf musculotendinous injury were enrolled. Scar thickness on B-mode imaging, new vessels according to PD grades, and SWE values in the muscle, musculotendinous junction, and tendon of the medial head of gastrocnemius were measured at 4, 8, and 12 weeks after injury. Scar thickness was significantly larger at 8 and 12 weeks compared with 4 weeks (P < .01 for both). Power Doppler grades at 4 and 8 weeks were significantly higher compared with 12 weeks (P < .01 for both). Shear wave elastographic values in the muscle on the injury side were significantly higher at 8 and 12 weeks compared with 4 weeks (P < .01 for both), whereas those in the musculotendinous junction on the injury side were significantly higher at 12 weeks compared with 4 and 8 weeks (P < .01; P = .01, respectively). B-mode imaging, PD imaging, and SWE can measure the healing process after musculotendinous injury of the gastrocnemius medial head.

Infected Baker’s cyst, diagnosed in the emergency department using POCUS

Baker’s cyst is a closed collection of fluid that forms in the posterior aspect of the knee. Usually, it appears as a non-painful inflammation in the popliteal fossa. In adults, its aetiology is secondary to problems that cause distension of the knee joint. It is often associated with rheumatoid arthritis and osteoarthritis. Occasionally, the cyst may become oversized and rupture with the consequent leakage of synovial fluid into adjacent tissues, presenting a clinical course similar to acute thrombophlebitis. Infection of a popliteal cyst is an uncommon complication and is associated with septic arthritis. In this paper, we present the case of a patient, an intravenous drug user (IVDU), who developed a spontaneous infection of a Baker’s cyst secondary to Staphylococcus aureus, which was diagnosed in the emergency department (ED) using point-of-care-ultrasound (POCUS).&#x0D; &#x0D; Figure 1. Within the posterior aspect of the left calf on the medial aspect there is an extremely large cystic lesion measuring 18.7 cm in length and 4 cm in width with no adverse features. The cystic lesion is communicating with the semimembranosus/medial head gastrocnemius bursa more proximally in the knee where it demonstrates internal echoes and synovial thickening and a single septation.

Variation of actin filament length in dogs.

As the smallest functional unit of force production, the sarcomeres are important in determining muscle function. Actin filament lengths, which are important in determining optimal sarcomere length for a species, have not yet been reported in dogs. This study aims to provide a species-specific value for actin filament length in dogs, while examining intraspecies, intermuscular and intramuscular variations. Muscle samples were taken from the tibialis anterior muscle, the lateral gastrocnemius muscle head and the medial gastrocnemius muscle head in 10 dogs including a Labrador, a Belgian Malinois, a Caucasian Shepherd, German Shepherds and some mixed-breed dogs. Actin filament lengths were determined through transmission electron microscopy. Mean actin filament length across all muscle samples was 0.90±0.01μm. The low intraspecies variation, combined with a lack of important inter- and intramuscular variation found in this study, affirms the use of a species-specific optimal sarcomere length of 1.89μm for canine muscles.

Morphological variants of nerve to gastrocnemius muscle, an anatomical guide to perform surgical dissection

SUMMARY Background. The precise knowledge about distribution of nerves supplying the gastrocnemius muscle is clinically important. The present study aimed to observe the morphological variations in the nerve supply of gastrocnemius in a sample South Indian population. Methods. The study included 38 formalin fixed adult cadaveric lower limbs. Variation in the number and branching pattern of the nerve to gastrocnemius muscle was studied. An imaginary line connecting the medial and lateral epicondyles of the femur, was considered as the reference line to study the topographical origin of the nerves. Results. It was observed that tibial nerve was giving one, two or three branches to the medial head of gastrocnemius muscle in 47.4%, 44.7% and 7.9% cases, respectively. The lateral head of gastrocnemius was receiving single, double or triple branch from tibia nerve in 60.5%, 34.2% and 5% cases, respectively. The nerve that innervated lateral head of gastrocnemius was also supplying soleus in 81.6% cases. The nerve to medial head was found at a higher level than the nerve to lateral head in 27 (71.1%) cases, whereas in 11 (28.9%) cases both were originating at the same level. In 76.3% cases, the nerve to MG was originating above the reference line and in 23.7% cases, below it. The nerve to LG was diverged below the reference line in 84.2% cases, at the reference line in 7.9% cases and above it in 7.9% cases. Conclusion. We report variations in the number and topography of nerves supplying the gastrocnemius muscle, that are enlightening to the operating plastic surgeon during the procedures like triceps surae nerve block and calf reduction. This data can be used as an anatomical guide to perform the surgical dissection

Test Yourself-Avulsion Injury of Medial Head of Gastrocnemius.

Test Yourself-Avulsion Injury of Medial Head of Gastrocnemius.

Test Yourself—Avulsion Injury of Medial Head of Gastrocnemius

Test Yourself—Avulsion Injury of Medial Head of Gastrocnemius

A protocol to prospectively assess risk factors for medial tibial stress syndrome in distance runners

BackgroundMedial tibial stress syndrome (MTSS) is a lower leg injury with a reported incidence rate of up to 35% in active individuals. Although numerous prospective studies have tried to identify risk factors for developing MTSS, managing the syndrome remains difficult. One risk factor yet to be extensively explored in MTSS development is reduced lower leg girth. Further investigation of reduced lower leg girth is required due to the important role lower leg musculature plays in attenuating ground reaction forces during the gait cycle. Therefore, the primary aim of this study is to ascertain whether lower leg muscle morphology and function contribute to the development of MTSS. Our ultimate aim is to identify potential risk factors for MTSS that can be targeted in future studies to better manage the injury or, preferably, prevent individuals developing MTSS.MethodsThis study will be prospective in design and will recruit asymptomatic distance runners. All participants will be tested at base line and participants will have their training data longitudinally tracked over the following 12 months to assess any individuals who develop MTSS symptoms. At base line, outcome measures will include bilateral measures of lower limb anthropometry; cross sectional area (CSA) and thickness of the tibialis anterior, peroneals, flexor digitorum longus, flexor hallucis longus and thickness of soleus, medial and lateral head of gastrocnemius. Tibial bone speed of sound, ankle dorsiflexion range of motion, strength of the six previously described muscles, foot alignment and ankle plantar flexor endurance will also be assessed. Participants will also complete a treadmill running protocol where three-dimensional kinematics, plantar pressure distribution and electromyography data will be collected.DiscussionThis study will aim to identify characteristics of individuals who develop MTSS and, in turn, identify modifiable risk factors that can be targeted to prevent individuals developing this injury.

Assessment of Passive Stiffness of Medial and Lateral Heads of Gastrocnemius Muscle, Achilles Tendon, and Plantar Fascia at Different Ankle and Knee Positions Using the MyotonPRO.

BackgroundThe aim of this study was to assess the passive stiffness of the medial and lateral gastrocnemius (MG and LG), Achilles tendon (AT), and plantar fascia (PF) at different ankle and knee positions.Material/MethodsStiffness was assessed using a portable hand-held device (MyotonPRO). In 30 healthy participants (15 males, 15 females) with the knee fully extended or flexed 90°, stiffness of the MG, LG, AT, and PF was measured at 50° plantar flexion, 0° (neutral position), and 25° dorsiflexion (not for AT) of the ankle joint by passive joint rotation.ResultsWith the knee fully extended, passive dorsiflexion caused significant increase in muscle stiffness (P<0.001), whereas AT and PF stiffness increased with passive ankle dorsiflexion regardless of knee position (P<0.001). Increased stiffness was observed in MG compared to LG (P<0.001) and at the 3-cm site of AT compared to the 6-cm site (P<0.05). Stiffness was greater in LG compared to MG at −50° plantar flexion (P<0.001) and was greater in MG compared to LG at 25° dorsiflexion (P<0.05). Stiffness of AT increased in a distal-to-proximal pattern: 0 cm >3 cm >6 cm (P<0.001).ConclusionsStiffness assessed by use of the MyotonPRO was similar assessments using other techniques, suggesting that the MyotonPRO is capable of detecting the variations in stiffness of MG, LG, AT, and PF at different ankle and knee positions.

Muscles Recruitment Pattern in People with and Without Active Upper Trapezius Myofascial Trigger Points in the Standing Posture

Background: Myofascial trigger points are known as the main reasons for the neck pain. Myofascial trigger points may change the coordination of cervical muscles and cause impaired proprioception. Objectives: The aim of this study was to investigate the onset of shoulder and cervical muscles activity and muscles recruitment pattern in patients with an active myofascial trigger point in the upper trapezius. Methods: 15 patient subjects (aged 26.80 ± 2.67 years) with one active myofascial trigger point in the upper trapezius and 15 control subjects (aged 27.73 ± 3.43 years) participated in this study. The subjects flexed their arms in response to a sound stimulus. The onset time of anterior deltoid was chosen as the initial point in showing the onset time of cervical paraspinal, lumbar paraspinal, upper trapezius, sternocleidomastoid, and medial head of gastrocnemius muscles. Results: The patient group represented a delay in the onset of muscles activity and altered muscle recruitment pattern compared to the control subjects (P < 0.001). However, the sternocleidomastoid muscle showed no delay in this group (P = 0.67). Conclusions: These results showed latency in the onset of muscles activity and altered muscles recruitment patterns. The altered muscles recruitment pattern may lead to changes in motor control strategies and poor control of movement. Finally, these changes can cause a poor control of movement and increase the possibility of damage to the shoulder and cervical muscles in patients with an active myofascial trigger point in the upper trapezius.