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Nocturnal leg cramps involving the foot and calf muscles are a frequent symptom adversely affecting sleep continuity. Mostly idiopathic, they may be secondary to other disorders, and can be acutely relieved but are often difficult to prevent.

OBJECTIVE To determine whether the lifetime prevalence and clinical characteristics of exercise-associated muscle cramping (EAMC) differ between runners entering a 21.1- versus 56-km road race. DESIGN Cross-sectional study. SETTING The 2012 to 2015 Two Oceans Marathon races (21.1 and 56 km), South Africa. PARTICIPANTS Participants were consenting race entrants (21.1 km = 44 458; 56 km = 26 962) who completed an online prerace medical screening questionnaire. INDEPENDENT VARIABLE A history of EAMC. MAIN OUTCOME MEASURES The main outcome variables were lifetime prevalence (%) and clinical characteristics (muscle groups affected, timing of occurrence, severity, frequency of serious EAMC, and self-reported treatment) of a history of EAMC. Differences between 56- and 21.1-km race entrants were explored (relative risk [RR]). RESULTS The lifetime prevalence of EAMC was 12.8%, which was higher in 56- (20.0%; 95% CI 19.5-20.6) versus 21.1-km race entrants (8.5%; 8.2-8.8) (P = 0.0001). In all entrants, the fourth quarter was the most common onset (46.4%), calf muscles were the most commonly affected (53.1%), and most EAMCs were of mild-to-moderate severity (95%). In 56- versus 21.1-km entrants, hamstring (RR = 1.7; 1.5-1.9) and quadriceps muscle groups (RR = 1.5; 1.3-1.7) were more frequently affected (P = 0.0001), the onset of EAMC during racing was less common in the first quarter (RR = 0.3; 0.2-0.4) (P = 0.0001), and serious EAMC was more frequent (RR = 1.6; 1.4-1.9) (P = 0.0001). CONCLUSIONS In 56- versus 21.1-km runners, a history of EAMC is 2 times more frequent and muscle groups affected, onset in a race, and severity of EAMC differed. The lifetime prevalence was lower than previously reported in other events. Risk factors associated with EAMC may differ between entrants for different race distances.

To examine the effects of dynamic tape on balance control in subjects with chronic ankle instability (CAI).This two group experimental pre- and post-treatment design included 18 individuals with CAI and 18 controls. The single-limb stance test with eyes open and closed, standing on a force plate (Accusway Plus; AMTI) for 30 s, was conducted before, 10 min (T1) and 24 h (T24) after a dynamic tape application over the gastrocnemius muscle. Outcome measurements were: mean sway velocity, sway area (circular area), and standard deviation of the body center of pressure path length in both mediolateral and anteroposterior directions. Individuals with poor (unable to perform a single leg test for at least 30 s, eyes closed) vs. good postural stability, were also compared.In both groups, a repeated analysis of variance demonstrated a significant time main effect on sway velocity (F = 14.95; p 0.001) and path length (F = 14.95; p 0.001) during eyes closed. Post-hoc analysis revealed a significant decrease in T1 values compared to baseline. When comparing individuals with poor vs good stability amongst the CAI group, a statistically significant interaction was observed between group, time on sway velocity and path length (F = 3.92; p 0.05) during eyes closed. In the poor postural group, most T1 values were significantly lower than baseline.Dynamic tape when applied to posterior calf muscles, enhanced balance control with no difference between CAI individuals and controls. The contribution of the tape was greater in those with poor postural stability.

Ultrasound at a frequency of 1 or 3 MHz is frequently used to treat various musculoskeletal conditions, but research on ultrasound operating at 38-50 kHz frequencies (US-KHz) is lacking. Study aimed to evaluate the short-term effect of US-KHz on pain pressure threshold (PPT), ankle dorsiflexion range of motion (ROM), and motor performance (the Side Hop Test) in subjects with a myofascial trigger point (TrP) in the calf muscle. US-KHz was applied to the area of the palpable TrP in the calf muscle for 10 minutes (continuous pulse, transducer head size 19.6 cm2, power 0.75-1.25 w/cm2) in twenty volunteers (18-45 years old). Significant improvements (p

In the literature of Ayurveda, Prameha (diabetes mellitus [DM]) is a disease where derangement is seen in urine with respect to its quantity and quality. The basic pathology involved in the disease is the Bahu, Abaddha Medas, and Kleda. Prameha can be well correlated to DM with respect to its pathology and symptoms. Here, we present the case of a 44-year-old male who came with complaints of restlessness, generalized weakness, giddiness, and pain in bilateral calf muscles for the past 4 months. Based on Ayurvedic examinations, he was diagnosed to have Margavarnajnya Madhumeha (~obese diabetic), suitable food, lifestyle, and medications were advised after assessing Prakriti, Dosha, etc. By Ayurvedic therapy, considerable improvement was seen in the quality of life. The case was followed up for 4 years and the patient’s condition was maintained well throughout, without any complications. This article reports a case of Type 2 DM on insulin therapy which was completely managed by Ayurvedic therapeutic modalities and all the oral hypoglycemic drugs along with insulin were withdrawn gradually during the course of the treatment.

Orthoses are often used for the treatment or prevention of injuries. The effect of orthoses on the activity of calf muscles such as the tibialis posterior (TP), flexor digitorum longus (FDL), and p...

Background: Football is one of the most popular sportsworldwide. Heading of the ball is an essential part of thegame. There is no much knowledge about the rule of lowerlimb muscles during the heading of the ball.Aim of Study: To examine actions of quadriceps, tibialisanterior, hamstrings, and calf muscles during the heading ofthe ball by using electromyography.Material and Methods: The actions of quadriceps, tibialisanterior, hamstrings, and calf muscles are studied by electro-myography in 15 young professional soccer players fromdifferent positions. The players headed the ball forwardlyfrom four different positions: Standing still; jumping; runningforward; running and jumping forward.Results: We found that all examined lower limb muscleswere active during the heading of the ball especially thetibialis anterior which produced more significant strengththan all other examined muscles in all different positions ofthe heading of the ball.Conclusion: This study suggests that healthy well trainedlower limb muscles especially the tibialis anterior may beessential for the accurate and effective heading of the ball inprofessional soccer players. In addition, professional playersshould avoid heading of the ball when lower limb musclesare injured especially tibialis anterior.

Abnormal foot motion is considered to be related to sports related injuries. This study aimed to identify the relationship between calf muscle activity and inter-segment coordination of the foot during single-leg drop jumps. Eleven healthy men participated and performed single-leg drop jumps from a 30-cm box. Muscle activity of the tibialis posterior (TP), flexor digitorum longus, peroneus longus (PL) and gastrocnemius were measured. The rearfoot and midfoot segment angle from landing to leaping were calculated according to the Rizzoli Foot Model and time scaled to 100%. A modified vector coding technique was employed to classify inter-segment coordination of every 1% into four patterns (in-phase, anti-phase, rearfoot phase,and midfoot phase). The relationship between percentage of each pattern and muscle activity levels were statistically analysed with correlation coefficient. The TP showed a significant positive correlation with percentage of in-phase in coronal plane (

Aim. The article aims to explore the features of a ball kicking bioelectric activity of lower limbs muscles in students playing snow football. Materials and methods. 30 males aged 21–25 years old were examined (3–4-year students): the control group consisted of 15 people playing football; the main group included 15 people playing snow football. Athletes kick a ball on a normal and on a slippery surface, imitation of a slippery surface was carried out using a GYMSTICK Power Slider 61131-PRO slide board. To record the bioelectric activity of the muscles, the Neuro-MVP-4 multifunctional computer system was used (Neurosoft, Ivanovo, Russia). The bioelectric activity of the calf muscles (the medial lateral head of the calf muscle), the rectus femoris muscle, and the adductor longus muscle was studied. Results: It has been shown that athletes playing football and snow football have different and largely opposite motor stereotypes of intermuscular coordination when kicking the ball in usual conditions. When this action is repeated under unusual conditions, stereotype distortion is observed. Football players are characterized by a partial stereotype distortion, while people playing snow football are almost completely disorganized on a normal surface. Conclusion: Football training for students playing various types of football should be carried out in different conditions and implement various strategies. In particular, it should be aimed at various muscle groups. Ball kicking in unusual conditions should be used carefully, as this can be accompanied by a negative transfer of skills and reduce the effectiveness of athletes’ performance.

The aim of this study was to compare the effectiveness of acute of contract–relax (CR) and contract–relax–antagonist–contraction (CRAC) targeting the quadriceps, hamstrings, anterior tibialis, and calf muscles and warm-up without stretching on medio-lateral (ML) and antero-posterior (AP) dynamic balance control in healthy young men applied by a physiotherapist in comparison to a control intervention without stretching. Twenty healthy young men between the age of 18 and 25 performed three interventions in randomized days after standard warm-up: CR intervention, CRAC intervention, and control intervention. ML and AP dynamic balance control was carried out before (Pre) and immediately after (Post) each intervention. Antero-posterior sway (AP sway) and medio-lateral sway (ML sway) under vision and no vision condition were analyzed by posturography. CRAC intervention improved significantly ML dynamic balance control by decreasing ML sway (vision, p = 0.006 and no vision, p

The natural neuromuscular model has greatly inspired the development of control mechanisms in addressing the uncertainty challenges in robotic systems. Although the underpinning neural reaction of posture control remains unknown, recent studies suggest that muscle activation driven by the nervous system plays a key role in human postural responses to environmental disturbance. Given that the human calf is mainly formed by two muscles, this paper presents an integrated calf control model with the two comprising components representing the activations of the two calf muscles. The contributions of each component towards the artificial control of the calf are determined by their weights, which are carefully designed to simulate the natural biological calf. The proposed calf modelling has also been applied to robotic ankle exoskeleton control. The proposed work was validated and evaluated by both biological and engineering simulation approaches, and the experimental results revealed that the proposed model successfully performed over 92% of the muscle activation naturally made by human participants, and the actions led by the simulated ankle exoskeleton wearers were overall consistent with that by the natural biological response.

Body sway, which is a slight movement that naturally occurs when a person stands, has attracted attention as an informative cue with which to identify people. In the field of kinematics, analytical studies have revealed that the movement of body sway varies when calf muscles are fatigued. However, the studies have not revealed whether the accuracy of identifying people is reduced by calf muscle fatigue. We investigate the identification accuracy for body sway signals taken from video sequences when fatiguing the target's calves. We find that the power spectral density of each frequency band of body sway is increased by fatigue and that the identification accuracy is significantly decreased. We also find that the magnitude of the velocity of body sway is greater in post-fatigue movement than in pre-fatigue movement.

Chiu, LZF and Daehlin, TE. Midfoot and ankle mechanics in block and incline heel raise exercises. J Strength Cond Res XX(X): 000-000, 2021-Although the heel raise exercise is performed to strengthen the calf muscles, the combination of calf muscle and ground reaction forces elicits moments that may deform the foot's longitudinal arch. The primary purpose of this investigation was to examine whether the foot muscles contribute to supporting the longitudinal arch during heel raises. The secondary purpose was to compare foot and ankle mechanical efforts between traditional block vs. 22° incline heel raises. Six women and 6 men performed heel raises with body mass plus a barbell loaded with 40% (BM + 40%) and 60% (BM + 60%) of their body mass. Three-dimensional motion analysis and force platform data were collected. The midfoot joint was evaluated from the angle between the forefoot and rearfoot (i.e., arch angle) and net joint moment, which may elevate or reduce the arch height. Midfoot joint arch elevator moment seemed to be greater for BM + 60% than BM + 40% (p < 0.05; Cohen's d = 1.24-1.61), with minimal change in arch angle (p < 0.05; Cohen's d = 0.15-0.19). Midfoot joint arch elevator and ankle plantar flexor moments seemed to be greater in incline vs. block heel raises for both loads (p < 0.05; Cohen's d = 0.58-0.67). The increase in midfoot joint arch elevator moment with trivial change in arch angle supports the hypothesis that the foot muscles contribute to longitudinal arch support during heel raises. Performing incline heel raises may be hypothesized to be more effective to stimulate foot and calf muscle adaptations than block heel raises.

BACKGROUND: Flexible flatfoot is associated with altered plantar pressure distribution, but it is not clear how muscle fatigue affects plantar pressure characteristics in flexible flatfoot and normal foot. OBJECTIVE: To investigate the effects of calf muscles fatigue on plantar pressure variables in flexible flatfoot and normal foot. METHODS: Twenty-five people with flexible flatfoot and twenty-five people with normal foot were included. The unilateral heel-rise test was used to induce calf muscles fatigue. Plantar pressure variables were collected during preferred walking immediately before and after fatigue. The two-way mixed-design ANOVA was used to determine the main effect of fatigue and the interaction between foot posture and fatigue. RESULTS: Fatigue caused medialization of the contact area under the forefoot and the maximum force under the heel and forefoot (p< 0.05). When examining the differences in the effects of fatigue between groups, the contact area under the medial heel increased with fatigue in flexible flatfoot but decreased in normal foot; moreover, the contact area and maximum force under the midfoot and the maximum force under the third metatarsal decreased with fatigue in flexible flatfoot but increased in normal foot (p< 0.05). CONCLUSIONS: Calf muscles fatigue caused medialization of the maximum force and contact area. Especially the midfoot was affected differently by fatigue in flexible flatfoot and normal foot.

The purpose of the study was to examine a long-term effect of repeated Wingate anaerobic training on anaerobic power of women basket ball players according to playing position. Participants(n=12) performed 4 sets of anaerobic training with 5-minute break between sessions twice per week during a year. Due to the games, total 7 trainings per month were given. Anaerobic capacity was measured by the Wingate power test and body composition was measured by the Bioelectrical Impedance Analysis (BIA). In addition, a line tape was used to measure leg circumference (e.g., quadriceps and calf muscles). As a result, 1. Anaerobic training showed the highest effectiveness when implementing 6-7 times per month. 2. Body composition and Leg circumference was significantly different according to playing positions 3. The Wingate anaerobic training significantly improved anaerobic capacity in majority of players whereas the center position did not show significant improvement. Findings indicate that repeated anaerobic training can be helpful interval training. Also, the optimal training strategy by playing positions may be recommended.

Objective To identify the role of hyperexcitable short-latency stretch reflexes (SLRs) on balance control in people with hereditary spastic paraplegia (PwHSP). Methods Sixteen PwHSP with triceps surae spasticity and 9 healthy control subjects were subjected to toes-up support-surface perturbations. EMG data were recorded from gastrocnemius, soleus and tibialis anterior. Furthermore, center-of-mass trajectories were recorded. Results PwHSP were less able to withstand the perturbations. Triceps surae SLRs (40–80 ms post perturbation) in PwHSP were increased compared to healthy subjects. Furthermore, a sustained triceps surae EMG activity at 220–320 ms post perturbation was observed in PwHSP, whereas control subjects demonstrated suppression of triceps surae activity. Center of mass trajectories started to diverge between PwHSP and controls only after ∼500 ms, with greater excursions being observed in the PwHSP. Conclusions The present results confirm that balance control is impaired in PwHSP. However, the late instant of center of mass divergence argues against a direct, causative role of hyperexcitable SLRs in the triceps surae. Significance We postulate that enhanced short-latency stretch reflexes of the triceps surae do not underlie poor balance control in PwHSP. Instead, we suggest the lack of suppression of later triceps surae activity to be the main cause.

Aim. To study the relationship of subjective and objective signs of chronic venous diseases (CVD) with the state of the autonomic nervous system (ANS) in men with arterial hypertension (AH).Material and methods. The object of the study were 74 men with AH at the age of 30-50 years with SBP level 148 (144-155) mm Hg. and DBP 101 (92-108) mm Hg. Two groups of 20 people were selected with the extreme parameters of vegetative index (Kerdo index).Results. The most common complaints in patients with severe parasympathicotonia were pain in the legs and fatigue when walking, cramps in the calf muscles, oedema and sural trophic disorders. An objective examination of patients with severe vagotonia revealed a more frequent occurrence of the leading symptom of CVD — oedema.Conclusion. AH with severe parasympathicotonia in men 30-50 years old is characterized by an increase in the frequency of subjective and objective signs of CVD, which indicates the role of ANS in the development of CVD in AH.

Peripheral artery disease (PAD) in the lower extremities often leads to intermittent claudication. In the present study, we proposed a low-dose DCE MRI protocol for quantifying calf muscle perfusion stimulated with plantar flexion and multiple new metrics for interpreting perfusion maps, including the ratio of gastrocnemius over soleus perfusion (G/S; for assessing the vascular redistribution between the two muscles) and muscle perfusion normalized by whole body perfusion (for quantifying the muscle’s active hyperemia). Twenty-eight human subjects participated in this Institutional Review Board-approved study, with 10 healthy subjects ( group A) for assessing interday reproducibility and 8 healthy subjects ( group B) for exploring the relationship between plantar-flexion load and induced muscle perfusion. In a pilot group of five elderly healthy subjects and five patients with PAD ( group C), we proposed a protocol that measured perfusion for a low-intensity exercise and for an exhaustion exercise in a single MRI session. In group A, perfusion estimates for calf muscles were highly reproducible, with correlation coefficients of 0.90–0.93. In group B, gastrocnemius perfusion increased linearly with the exercise workload ( P < 0.05). With the low-intensity exercise, patients with PAD in group C showed substantially lower gastrocnemius perfusion compared with elderly healthy subjects [43.4 (SD 23.5) vs. 106.7 (SD 73.2) ml·min−1·100 g−1]. With exhaustion exercise, G/S [1.0 (SD 0.4)] for patients with PAD was lower than both its low-intensity level [1.9 (SD 1.3)] and the level in elderly healthy subjects [2.7 (SD 2.1)]. In conclusion, the proposed MRI protocol and the new metrics are feasible for quantifying exercise-induced muscle hyperemia, a promising functional test of PAD.NEW & NOTEWORTHY To quantitatively map exercise-induced hyperemia in calf muscles, we proposed a high-resolution MRI method shown to be highly reproducible and sensitive to exercise load. With the use of low contrast, it is feasible to measure calf muscle hyperemia for both low-intensity and exhaustion exercises in a single MRI session. The newly proposed metrics for interpreting perfusion maps are promising for quantifying intermuscle vascular redistribution or a muscle’s active hyperemia.

Current clinical MRI evaluation of musculature largely focuses on nonquantitative assessments (including T1-, T2- and PD-weighted images), which may vary greatly between imaging systems and readers. This work aims to determine the efficacy of a quantitative approach to study the microstructure of muscles at the cellular level with the random permeable barrier model (RPBM) applied to time-dependent diffusion tensor imaging (DTI) for varying diffusion time. Patients (N = 15, eight males and seven females) with atrophied calf muscles due to immobilization of one leg in a nonweight-bearing cast, were enrolled after providing informed consent. Their calf muscles were imaged with stimulated echo diffusion for DTI, T1-mapping and RPBM modeling. Specifically, After cast removal, both calf muscles (atrophied and contralateral control leg) were imaged with MRI for all patients, with follow-up scans to monitor recovery of the atrophied leg for six patients after 4 and 8 weeks. We compare RPBM-derived microstructural metrics: myofiber diameter, a, and sarcolemma permeability, κ, along with macroscopic anatomical parameters (muscle cross-sectional area, fiber orientation, , and T1 relaxation). ROC analysis was used to compare parameters between control and atrophied muscle, while the Friedman test was used to evaluate the atrophied muscle longitudinally. We found that the RPBM framework enables measurement of microstructural parameters from diffusion time-dependent DTI, of which the myofiber diameter is a stronger predictor of intramuscular morphological changes than either macroscopic (anatomical) measurements or empirical diffusion parameters. This work demonstrates the potential of RPBM to assess pathological changes in musculature that seem undetectable with standard diffusion and anatomical MRI.

Surface electromyography (EMG) has been used to estimate muscle work and physiological burden of the whole body during human movements. However, there are spatial variations in surface EMG responses within individual muscles. The aim of this study was to investigate the relation between oxygen consumption and surface EMG responses of lower leg muscles during walking at various speeds and to quantify its spatial variation within an individual muscle. Nine young males walked on a treadmill at four speeds: preferred minus 1 km/h, preferred, preferred plus 1 km/h, and preferred plus 2 km/h, and the metabolic response was measured based on the expired gas. High-density surface EMG of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles was performed using 64 two-dimensional electrode grids. Correlation coefficients between oxygen consumption and the surface EMG amplitude were calculated across the gait speeds for each channel in the electrode grid and for individual muscles. Mean correlation coefficients across electrodes were 0.69–0.87 for the four individual muscles, and the spatial variation of correlation between the surface EMG amplitude and oxygen consumption within an electrode grid was significantly greater in MG muscle than in TA muscle (Quartile deviations: 0.24 for MG and 0.02 for TA, p < 0.05). These results suggest that the physiological burden of the whole body during gait at various speeds can be estimated from the surface EMG amplitude of calf muscles, but we need to note its spatial distribution within the MG muscle.

Muscle injuries are the most common trauma in team and individual sports. The muscles most frequently affected are those of the lower limb, and in particular hamstrings, adductors, rectus femoris and calf muscles. Although several scientific studies have tried to propose different rehabilitation protocols, still too often the real rehabilitation process is not based on scientific knowledge, especially in non-elite athletes. Moreover, the growing use of physical and instrumental therapies has made it increasingly difficult to understand what can be truly effective. Therefore, the aim of the present paper is to review proposed therapeutic algorithms for muscle injuries, proposing a concise and practical summary. Following a three-phase rehabilitation protocol, this review aims to describe the conservative treatment of indirect structural muscle injuries, which are the more routinely found and more challenging type. For each phase, until return to training and return to sport are completed, the functional goal, the most appropriate practitioner, and the best possible treatment according to current evidence are expressed. Finally, the last section is focused on the specific exercise rehabilitation for the four main muscle groups with a structured explanatory timetable.

To the Editor: We read with interest the article, “The Effects of Myofascial Trigger Point Injections on Nocturnal Calf Cramps.” 1 In this study, the investigators have raised awareness of myofascial trigger point (MTrP) in calf muscles resulting in nocturnal calf cramp (NCC), which we commonly see in our daily practice, and they discussed diagnosis of NCC. Alternatively, they offered treatment with local anesthetic injection to the trigger points in NCC. However, dry needling (DN) was not mentioned among the treatment modalities for NCC in the article. We wish to put forward that DN may be considered for calf muscle trigger point treatment in NCC.

Orthotopic models are based on the implantation of tumor cells directly into the organ of origin, which allows interaction between the cells and the surrounding host tissues.Here we describe a modified version of an orthotopic model that closely recapitulates the steps required for metastasis development in Ewing sarcoma: tumor cells are injected into the calf muscles of the mouse, and once the tumor reaches a certain volume, the muscles containing the tumor are surgically resected. This procedure involves a nonaggressive surgery of the muscle which allows for the survival of the mouse during a period of time that is long enough to enable the development of distant metastases. This spreading of tumor cells to metastatic sites in other organs takes place by a physiological mechanism similar to what occurs in human Ewing sarcoma.

Our study focuses on design and fabrication of multi-channel (ideally 8-Channel) sEMG acquisition (Surface EMG) device using an Instrumentation amplifier AD620 for its low noise applications and extract sEMG signals from a cluster of test subjects, observe their muscle patterns, primarily focusing on its scope in leg muscles with its target points near Quadriceps, Hamstrings, Calf muscles, and analyze multiple gait patterns to study the cause and effects of Knee Osteoarthritis. Also, an efficient multi-channel data visualization and analysis tool on MATLAB has been designed with the sEMG device as mentioned above, working in tandem. The device will have the provision of I2C communication and with the help of this, simultaneous acquisition and parameter analysis of multi-channel signals can be achieved, which plays a key role in biomedical signal analysis.

In order to identify the road slope by leg EMG signal, we use OpenSim to analyze the relationship between ankle movement and calf muscle length; tibialis anterior muscle and gastrocnemius muscle are selected in the EMG signal acquisition test; the EMG signals of chosen muscles are obtained when walking on seven different slope roads; BP neural network is used to identify the signal after time-domain (iEMG, VAR, and RMS) and frequency-domain(MF and MPF) feature analysis. The results show that the EMG signals of tibialis anterior muscle and gastrocnemius muscle can identify the slope of road with an average recognition rate of 87.68%. The results provide a basis for human-computer interaction technology with EMG signal as input.

Context and Aims: Effects of practicing yoga in diabetic mellitus (DM) patients have been identified to improve in control of blood glucose levels. The purpose of this work is to evaluate changes in blood flow of calf muscles after specific yoga postures for patients with DM using magnetic resonance imaging (MRI) techniques. Time of flight (TOF) magnetic resonance angiography maximum intensity projection (MIP), T1 maps, T2 maps, and diffusion-weighted Imaging are performed on volunteers and DM patients both pre- and post-exercise. Materials and Methods: TOF MIP, T1 maps with variable flip angles, and T2-weighted spin-echo imaging were performed on four volunteers (aged 30 ± 5) and DM patients (aged 32–68) preexercise, on a 1.5 T Siemens scanner. The total acquisition time was 6 min 20 s. Each volunteer and DM patient were then requested to perform yoga postures Supta Padangusthasana, Utkatasana, and Calf raise for 6 min 30 s at maximum effort, outside the scanner, and subsequently rescanned. To calculate significant signal increase, region of interests was drawn on TOF MIP coronal images in arteries of calf muscles. Student t-tests were performed to determine statistical significance. Results: Among volunteers, a significant signal increase in arteries of calf muscles was noticed, signal intensity graphs were plotted. In DM patients, signal increase in TOF MIP, T2-weighted images were seen in specific arteries (posterior, anterior tibial, and posterior tibial) of calf muscles postexercise. Discussion and Conclusions: The study indicates that yoga has a positive short-term effect on multiple DM-related foot complications. This study depicts that MRI provides potential insight into the benefits of yoga for DM patients through deriving biomarkers for preventive medicine relevant to yoga interception.

Background Previous studies reported a relationship between postural sway and force variability of the plantar flexor muscles (PFM), such that less force variability related to lower postural sway; however, this association does not seem to exist in older adults. Research question This study investigated the effect of force stability training of the PFM on force variability (FV) of these muscles and postural sway in female older adults. Methods Thirty female older adults were divided into three groups: TG5 (n = 10), who trained at 5% of maximum voluntary isometric contraction (MVIC) of the PFM; TG10 (n = 10), who trained at 10 % of MVIC of the PFM; and CG (n = 10) who did not perform any specific training for the PFM. Postural sway was evaluated during upright bipodal posture. Postural sway and FV of the PFM were assessed before and after the training period. Participants trained once a week for four weeks. Results After the training period, the FV decreased significantly for both TG5 (pre = 3.26 ± 0.83; post = 2.53 ± 0.60 N) and TG10 (pre = 3.50 ± 0.72; post = 2.85 ± 0.86 N), but the mean sway amplitude increased for both TG5 (pre = 0.017 ± 0.03; post = 0.19 ± 0.04 cm) and TG10 (pre = 0.14 ± 0.04; post = 0.16 ± 0.04 cm). Significance The force stability training decreased the FV of the PFM, but this decrease was insufficient to reduce postural sway in female older adults.

The purpose of the study was to compare kinematics and muscle activity between two variations of unilateral squats under different stability conditions. Twelve male volunteers (age: 23±5 years, mass: 80±17 kg, height: 1.81±0.11 m, strength-training experience: 4.3±1.9 years) performed four repetitions with the same external load (≈4RM). Two variations (with the non-stance leg forwards vs. backwards) were performed in a Smith-machine and free-weight condition. The variables were barbell velocity, lifting time and surface electromyography activity of the lower extremity and trunk muscles during the descending and ascending phase. The main findings were 1) peak force was higher when performing the unilateral squats in the Smith machine; 2) peak ascending barbell velocity increased from repetition 3–4 with free weight; and 3) muscle activity from the rectus femoris, vastus lateral, biceps femoris, gluteus medius, and erector spinae increased with repetitions, whereas gluteus, and medial vastus and shank muscles were affected by the conditions. It was concluded that more peak force could be produced because of increased stability. However, peak barbell velocity increased from repetition to repetition in free-weight unilateral squats, which was probably because the participants grew more comfortable. Furthermore, increased instability causes more gluteus and vastus medial activation and foot variations mainly affected the calf muscles.

BACKGROUND Diffusion tensor imaging (DTI) has been used to characterize calf skeletal muscle architecture. PURPOSE To assess the diffusional properties of the calf muscles of subjects with and without diabetes, at rest and during isometric plantarflexion exercise. STUDY TYPE Prospective. SUBJECTS Twenty-six subjects in two groups: 13 healthy and 13 subjects with type 2 diabetes (DM); each group consisted of seven females and six males. FIELD STRENGTH/SEQUENCE 3T/2D single-shot spin echo planar imaging. ASSESSMENT Fractional anisotropy (FA), mean diffusivity (MD), diffusion eigenvalues, and fiber tracking indices were obtained from the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) muscles of the calf at rest and during isometric plantarflexion exercise. STATISTICAL TESTS We used a combination of nonparametric (Wilcoxon) and parametric (t-test) statistical assessments. RESULTS The medial gastrocnemius muscle had more indices with significant differences between the two groups (six indices with P

The purpose of this study was to investigate the intensity-specific regenerative effects of microcurrent therapy on gastrocnemius muscle atrophy induced by cast-immobilization in rabbits. Fifteen rabbits were randomly allocated to 3 groups after cast removal: cast-immobilization and sham microcurrent therapy for 2 weeks (group 1); cast-immobilization and microcurrent therapy (25 μA) for 2 weeks (group 2); cast-immobilization and microcurrent therapy (5,000 μA) for 2 weeks (group 3). Clinical parameters [calf circumference, compound muscle action potential (CMAP) of the tibial nerve, thickness of gastrocnemius muscle], cross sectional area of gastrocnemius muscle fibres, and immunohistochemistry was evaluated. The clinical parameters representing mean atrophic changes in group 2 were significantly lower than those in group 3. The cross sectional area of the gastrocnemius muscle fibres and immunohistochemical parameters in group 2 were significantly greater than those in group 3. The results showed that low-intensity microcurrent therapy can more effectively promote regeneration in atrophied gastrocnemius muscle than high-intensity microcurrent therapy.

Introduction: Appropriate muscle recruitment has a significant role in the stabilization of joints. The aim of this study is to investigate the effects of six weeks Plyometric training on performance and the feed-forward activation of calf muscles in active females with functional ankle instability in single leg drop landing. Materials & methods: Thirty active females with functional ankle instability participated in this quasi-experimental study. The experimental group underwent six weeks of Pi-Yin Hung Plyometric training protocol during the period of 18 sessions. In order to assess the performance, functional tests (lateral hop and multiple hop tests) and ankle joint function assessment tool were used. Electrical activation assessments of peroneus longus, tibialis anterior and gastrocnemius muscles (in single leg drop landing task) were completed in the pre-test and post-test (after six weeks). SPSS Software version 20 was used in order to analyze the data (p less-than 0.05). Finding: Results revealed that after the implementation of six weeks Plyometric training, multiple hops testing time dropped significantly and lateral hop testing distance had a significant increase. A significant increase in the feed-forward activation of peroneus longus and medial gastrocnemius was seen (p≤0.05), but there were no significant changes at the feed-forward activation of tibialis anterior (p less-than 0.05). Discussion & conclusions: Plyometric training by changing the feed-forward activation of peroneus longus and medial gastrocnemius muscles, improved lower extremity performance in patients with functional ankle instability and should be incorporated into rehabilitation programs for those with functional ankle instability.

Purpose 23Na MRI demonstrated increased tissue sodium concentrations in a number of pathologies. Acute atrophy results in muscle fibre volume shrinking that may result in a relative increase of extracellular volume and might affect sodium concentration. Thus, we hypothesized that local unloading of the calf muscles would lead to a decrease in muscle volume and an increase in muscle tissue sodium concentration. Method One lower leg of 12 healthy male subjects was submitted to a 60 day long period of unloading using the Hephaistos orthosis, while the other leg served as control. 23Na MRI and 2D PD-weighted Dixon turbo spin echo were obtained from the control and orthosis leg using a 3T scanner. For quantification, a sodium reference phantom was used with 10, 20, 30, and 40 mmol/L NaCl solution. Result Tissue sodium concentration (TSC) increased as an effect of unloading in the orthosis leg. Relative increases were 17.4 ± 16.8% (P = 0.005) in gastrocnemius medialis muscle, 11.1 ± 12.5 (P = 0.037) in gastrocnemius lateralis muscle, 16.2 ± 4.7% (P < 0.001) in soleus muscle, 10.0 ± 10.5% (P = 0.009) in the ventral muscle group, and 10.7 ± 10.0% (P = 0.003) in the central muscle group, respectively. TSC in the control leg did not significantly change. In the orthosis leg, muscle volume decreased as follows: medial gastrocnemius muscle: −5.4 ± 8.3% (P = 0.043) and soleus muscle: −7.8 ± 15.0% (P = 0.043). Conclusion Unloading atrophy is associated with an increase in muscle sodium concentration. 23Na MRI is capable of detecting these rather small changes.

Summary Objective Muscle stretching is plenty used prior to training and competition. Considering the importance of balance control in performance, muscle stretching is expected to have positive effects on balance. However, there is a lack of studies investigating the effects of contract-relax proprioceptive neuromuscular facilitation (CR PNF) stretching on balance control. The purpose of this study was to investigate the effects of CR PNF stretching on static postural balance. Methods Fourteen subjects were tested before and after a 5-minute cycle warm-up followed by 10 minutes of CR PNF stretching (stretching condition) and the same cycle warm-up with 10-minute rest periods (control condition). The four muscle groups stretched were the quadriceps, hamstrings, anterior tibialis, and calf muscles of both legs in an alternating manner. Postural balance was assessed in a bipedal static stance before and after each condition with eyes opened (EO) and eyes closed (EC). Results No significant interactions for any postural parameters. However, there was a significant main effect of condition for sway area (P 0.05). Conclusion It appears that the stretching and control conditions impaired static balance control by increasing postural sway. CR PNF stretching was unable to compensate for the warm-up and its effects of induced alteration in postural balance.

The majority of motor unit studies were performed predominantly on calf muscles, where three types of units: S, FR and FF were found. These muscles are involved in postural activity, walking, running and jumping. The properties of foot muscles that perform other functions, e.g. scratching (in animals), and are purely co-active with calf muscles, are poorly known. The aim of the present study was to investigate the contractile properties of motor units in the flexor digitorum brevis. Fifty-six motor units were studied in male Wistar rats. Several methods of fast/slow motor unit categorization, presence of sag, contraction time values, and 20 Hz index, did not allow the separation of the studied motor units into discrete clusters. Therefore, motor units were divided into two groups: fatigable and resistant to fatigue, based on the fatigue index with the border value of 0.5 (although the distribution of the index was not bimodal). The fatigable motor units were stronger and faster compared to the resistant ones. In conclusion, the distribution of motor unit contractile properties in the studied foot muscle was continuous and indicated a lack of three separate physiological types of motor units that usually occurs for the majority of hindlimb muscles. This discrepancy appears to be associated with differences in the typical forms of motor unit activity in distinct muscles.

Background Diffusion tensor imaging (DTI) is a non-invasive MR technique widely employed to study muscle anatomy. DTI parameters have been used to investigate microstructural changes dependent on demographic factors or transient condition such as exercise. The present study is aimed at investigating the diffusion parameters changes of the human calf muscles after a 3-months strength training protocol. Methods Ten young men were trained for improving size and strength of the medial (GCM), lateral gastrocnemius (GCL) and soleus (SL) three times a week, with at least 24 hours between training sessions, for a period of three months. Diffusion weighted magnetic resonance images were acquired at the beginning of the training period (TPRE) and at three months (TPOST) using a 3T scanner. The fractional anisotropy (FA), mean diffusivity (MD) and tensor eigenvalues (λ1, λ2, λ3) were derived from the diffusion weighted imaging data. Results We found a significant increase in λ1, λ2, λ3 and MD values and muscle volumes between TPRE and TPOST in all the examined muscles both for the left and right side. No significant differences were highlighted for FA. Conclusions DTI enables the investigation of muscle microstructure, allowing for the assessment of diffusion parameters variation of the muscle tissue in response to training thus being a useful tool to investigate physiological and pathological changes in skeletal muscle microstructure which could be employed to test the outcomes and the effectiveness of a given training protocol.

In this chapter and in the Chaps. 9– 11 are presented some examples of conservative treatment protocol following indirect muscular lesions. The protocols are dedicated to indirect lesions of the quadriceps femoris (Chap. 8), hamstrings (Chap. 9), adductor muscles (Chap. 10), and calf muscles (Chap. 11). The injuries of these four muscle groups account for 80–90% of all indirect muscle injuries (Hallen and Ekstrand 2014; Crema et al. 2016; Walden et al. 2018). The different phases of the protocols are conformed to the biological phases of muscle tissue repair illustrated in the chapter. The number of the series proposed per exercise must be interpreted as indicative, as well as the recovery time between the series. The load to be used in the proposed exercises has not been intentionally indicated as it must be calibrated on the muscular characteristics of the subject.

The primary goal of this study was to evaluate arterial transit time (ATT) in exercise‐stimulated calf muscles as a promising indicator of muscle function. Following plantar flexion, ATT was measured by dynamic contrast‐enhanced (DCE) MRI in young and elderly healthy subjects and patients with peripheral artery disease (PAD). In the young healthy subjects, gastrocnemius ATT decreased significantly (P

Objective Toe walking due to progressive shortening of the calf muscles is common in people with hereditary spastic paraplegia. Achilles tendon lengthening is a treatment option, but clinicians are often hesitant to use this procedure, as it may result in weakening of the calf muscles and, subsequently, in reduced ankle power and knee instability during the stance phase of gait. We report here a case report supporting that these negative side-effects can be avoided in well-selected people with hereditary spastic paraplegia. Method Bilateral Achilles tendon lengthening, combined with bilateral tenotomy of the tibialis posterior and toe flexors, was performed in a 29-year-old woman with uncomplicated hereditary spastic paraplegia who experienced progressive gait instability due to shortening of the soleus and gastrocnemius muscles (resulting in irreducible pes equinus). Results Bilateral Achilles tendon lengthening resulted in improvement in both subjective and objective outcomes. Self-selected gait speed improved from 0.75 m/s before surgery to 1.07 m/s after surgery (p < 0.001). Knee instability during the stance phase did not occur post-surgery. The ankle moment trajectories normalized after surgery, while peak ankle powers increased. Conclusion Correction of bilateral irreducible pes equinus by Achilles tendon lengthening may improve gait capacity in well-selected subjects with hereditary spastic paraplegia. LAY ABSTRACT Toe walking due to shortening of the calf muscles is common in people with hereditary spastic paraplegia. This case report supports that lengthening of the calf muscles (Achilles tendon lengthening) may improve gait in well-selected people with hereditary spastic paraplegia.

Quantifying muscle water T2 (T2 -water) independently of intramuscular fat content is essential in establishing T2 -water as an outcome measure for imminent new therapy trials in neuromuscular diseases. IDEAL-CPMG combines chemical shift fat-water separation with T2 relaxometry to obtain such a measure. Here we evaluate the reproducibility and B1 sensitivity of IDEAL-CPMG T2 -water and fat fraction (f.f.) values in healthy subjects, and demonstrate the potential of the method to quantify T2 -water variation in diseased muscle displaying varying degrees of fatty infiltration. The calf muscles of 11 healthy individuals (40.5 ± 10.2 years) were scanned twice at 3 T with an inter-scan interval of 4 weeks using IDEAL-CPMG, and 12 patients with hypokalemic periodic paralysis (HypoPP) (42.3 ± 11.5 years) were also imaged. An exponential was fitted to the signal decay of the separated water and fat components to determine T2 -water and the fat signal amplitude muscle regions manually segmented. Overall mean calf-level muscle T2 -water in healthy subjects was 31.2 ± 2.0 ms, without significant inter-muscle differences (p = 0.37). Inter-subject and inter-scan coefficients of variation were 5.7% and 3.2% respectively for T2 -water and 41.1% and 15.4% for f.f. Bland-Altman mean bias and ±95% coefficients of repeatability were for T2 -water (0.15, -2.65, 2.95) ms and f.f. (-0.02, -1.99, 2.03)%. There was no relationship between T2 -water (ρ = 0.16, p = 0.07) or f.f. (ρ = 0.03, p = 0.7761) and B1 error or any correlation between T2 -water and f.f. in the healthy subjects (ρ = 0.07, p = 0.40). In HypoPP there was a measurable relationship between T2 -water and f.f. (ρ = 0.59, p