Muscle Belly Research Articles

Three in one - unusual palmaris longus muscle anatomical variation.

The palmaris longus muscle (PLM) is one of the most variable muscles in human body, pre-senting a wide range of morphological variants such as reversed course, biventer muscle, bi-furcated tendon or total agenesis. Their clinical impact is particularly important in diagnosis and treatment of carpal tunnel syndrome and reconstructive surgery. We present a case of PLM including a previously undescribed combination of variations. A routine dissection of male cadaver aged approximately 60 demonstrated a biventer muscle, with superior and inferior belly being interrupted by a long tendon. The inferior belly passed deep to the flexor retinaculum and its terminal tendon connected to flexor digitorum superfi-cialis tendon for 5th finger. The clinical importance of variations found have been described separately, including unsuita-bility of biventer muscles for tendon reconstruction and increased risk for developing carpal tunnel syndrome in patients with PLM tendon passing deep to the flexor retinaculum. In conclusion, as another variation of PLM is described, it is crucial to bear in mind the poten-tial morphological types of the muscle in diagnosis and treatment of patients, especially in surgery of the hand and forearm.

A methodological approach for collecting simultaneous measures of muscle, aponeurosis, and tendon behaviour during dynamic contractions.

Skeletal muscles and the tendons that attach them to bone are structurally complex and deform non-uniformly during contraction. While these tissue deformations dictate force production during movement, our understanding of this behaviour is limited due to challenges in obtaining complete measures of the constituent structures. To address these challenges, we present an approach for simultaneously measuring muscle, fascicle, aponeurosis, and tendon behaviour using sonomicrometry. To evaluate this methodology, we conducted isometric and dynamic contractions in in situ rabbit medial gastrocnemius. We found comparable patterns of strain in the muscle belly, fascicle, aponeurosis, and tendon during the isometric trials to those published in the literature. For the dynamic contractions, we found that our measures using this method were consistent across all animals and aligned well with our theoretical understanding of muscle-tendon unit behaviour. Thus, this method provides a means to fully capture the complex behaviour of muscle-tendon units across contraction types.

Subcutaneous Anterior Transposition With Modified Procedures to Prevent Recurrence Associated With the Transposed Ulnar Nerve.

Subcutaneous anterior transposition of the ulnar nerve is a common surgical treatment for cubital tunnel syndrome. However, there are surgical failures associated with the new compressive sites at the edge of flexor carpi ulnaris (FCU) and resubluxation posterior to the medial epicondyle of the transposed nerve. To reduce the muscle volume at the edge of FCU, we approach the ulnar nerve by dividing the muscle belly of the FCU humeral heads. This procedure can reduce repeated traction forces on the transposed nerve at the edge of the FCU. To keep the transposed ulnar nerve anteriorly, we use a fat flap including the membranous superficial fascia. This flap can softly stabilize the ulnar nerve and act as a pliable cover to prevent perineural scarring or further constriction around the flap. Ninety-three elbows in 90 patients who had undergone this procedure for cubital tunnel syndrome were evaluated. According to Messina's criteria, the numbers of patients showing excellent, good, fair, and poor recovery were 41 (44%), 47 (51%), 5 (5%), and 0 (0%), respectively. Most patients experience resolution of symptoms and good functional outcomes. None of the patients suffered recurrence, infection, or nerve injury.

An anatomical variant of the posterior branch of the great auricular nerve: A case report and a short review of the literature

The great auricular nerve (GAN) is a sensory cutaneous nerve, which provides sensory innervation to the skin overlaying auricle, parotid gland, and mastoid region. The emergency of GAN is located at Erb’s point over the posterior burden of the belly of the sternocleidomastoid muscle (SCM). During its course, it normally bifurcates in a pair of, respectively, posterior and anterior, branches. The latter one then further divides into superficial and deep branches. Some different anatomical patterns of GAN branches were reported in the literature to underline the high variability of the GAN course. The aim of this case report is to underline a particular anatomical variant of a posterior branch of GAN we recently observed. It was characterized by an anomalous bifurcation involving two different groups of fibers, within the same field of innervation, which had an independent course toward the auricular lobe. To promptly face such a somewhat unexpected anomaly, besides the basic recommendation to surgeons of mastering a good knowledge of the high variability of the anatomy of GAN, a careful dissection around the SCM is believed to help the surgeon to recognize other anatomical variants of GAN course with the aim to preserve it.

Anatomic study of flexor carpi ulnaris and brachioradialis muscles and their implication in reconstructive surgeries

Management of soft tissue loss around the posterior aspect of the elbow region is most challenging for clinicians, as it may require reconstructive methods for the better healing of wounds. One of the options for reconstructive surgery is local muscle rotational flaps by the flexor carpi ulnaris (FCU) and brachioradialis (BR). This study aimed to explore the morphometry and vascular anatomy of FCU and BR. Thirty formalin-embalmed cadaveric upper extremities (16 right and 14 left) were utilized for this study. The average length of the FCU muscle belly was 28.96 ±2.16 cm within a range of 24.3 to 32.5 cm, and the average length of the tendon was 10.05 ± 2.2 cm, with a range of 6.9 to 14.3 cm. The number of vascular pedicles for FCU was one in 5, two in 21, and three and four in 2 specimens respectively. All the pedicles arose from the ulnar artery. The average length of the BR muscle was 28.2 ±3.58 cm, with a range of 22.8 to 36.8 cm, and the average length of its tendon was 8.2 cm, with a range of 5.7 to 13.5 cm. In 90% of specimens, BR had only one vascular pedicle and in 10% there were two pedicles. These pedicles arose from the radial recurrent artery and the radial artery. Detailed morphometric and topographic anatomy of the vascular pedicles of FCU and BR are provided in this study, which can be considered the morphological database for the South Indian population.

Relationship to the superficial radial nerve and anatomic variations of the first extensor compartment in Thai population: a basis for successful de Quervain tenosynovitis treatment.

Knowledge of the superficial radial nerve (SRN) relationship and anatomic variations of the first extensor compartment (1st EC) will contribute to a better outcome of de Quervain tenosynovitis treatment. We dissected 87 embalmed cadaveric wrists to determine the relationship of the SRN, the 1st EC length, distance from the proximal and distal 1st EC borders to radial styloid process (RSP), abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendon slip numbers, and the presence of septum. Our results revealed SRN crossing over the 1st EC in 59.5%. The lateral branch of the superficial radial nerve to the 1st EC midline in most cases (61.9%) except for one specimen, where lateral antebrachial cutaneous nerve was the closest. Distances from proximal and distal 1st EC borders to the RSP were 19.7±4.1 mm and 7.6±1.8 mm, respectively. Extensor retinaculum (ER) width over 1st EC (1st EC length) was 14.8±3.2 mm. Complete and incomplete septa were found in 17.2%, and 42.5%, respectively. The most frequent APL tendon slip number in the compartment was two in overall 47 specimens (54.0%). Almost all compartments (85 specimens; 97.7%) contained one EPB tendon slip. We detected bilateral EPB absence in one cadaver. Moreover, we recorded a tendon slip from extensor pollicis longus traveling into 1st EC bilaterally in one cadaver and observed the EPB muscle belly extension into 1st EC in 9 wrists. Awareness of 1st EC anatomic variations would be essential for successful surgical and nonsurgical outcomes.

Association Between Muscle Growth and Transcription of a Mutant MSTN Gene in Olive Flounder (Paralichthys olivaceus).

Myostatin (MSTN, also known as growth differentiation factor-8 (GDF-8)), a member of the transforming growth factor β (TGF-β) superfamily, functions as a negative regulator of skeletal muscle development and growth. However, it is also expressed in a wide range of tissues in fish and thus may have more diverse roles in this group than in mammals. In this study, we assessed the genome-wide transcriptional expression pattern associated with the CRISPR/Cas9-mutated MSTN gene in the olive flounder (Paralichthys olivaceus) in association with changes in cell proliferation and transportation processes. There were no differences in the hepatosomatic index, and the growth of male and female fish increased in the F1 progeny of the MSTN mutants. Furthermore, the histopathological analysis showed that myostatin editing resulted in a 41.24% increase in back muscle growth and 46.92% increase in belly muscle growth in male flounder compared with normal flounder, and a 16.01% increase in back muscle growth and 14.26% increase in belly muscle growth in female flounder compared with normal flounder. This study demonstrates that editing of the myostatin gene enhances muscle growth in olive flounder, with a notably more pronounced effect observed in males. Consequently, myostatin-edited male flounder could represent a valuable asset for the flounder aquaculture industry.

Never undescribed four - headed plantaris muscle.

The plantaris is a small muscle of the superficial posterior compartment of the leg. It originates at the lateral supracondylar line of the femur and the knee joint capsule, from where it continues distally, forming a long and slender tendon distally attached to the calcaneal tuberosity. During standard anatomical dissection four-headed plantaris muscle was found and all of its heads connected to each other as a single muscle belly passing into tendinous structure which was distally attached as a standard plantaris muscle. The first head originated from the popliteal surface of the femur. The second one was originated from distal Kaplan fiber. In turn, the third and fourth heads were proximally attached to the lateral femoral epicondyle. Knowledge about morphological variations is necessary because of its potential clinical significance, which means not only neurovascular compressions, but also surgical procedures.

Difference in Stiffness between Biceps Brachii Muscle Bellies Using Shear Wave Elastography

The Shear Wave Elastography of muscles can provide real-time information on the stiffness of muscles; however, the difference in stiffness between biceps brachii muscle bellies requires more research. Understanding the variables that affect muscle stiffness will assist in the development of Shear Wave Elastography as a diagnostic tool for muscle stiffness pathologies. This study’s aim is to determine the Shear Wave Velocity of the short and long head of biceps brachii and the change in stiffness with elbow flexion to create a reliable protocol for pathological muscle assessment. The muscle belly of the short and long heads of bilateral biceps brachii of 38 healthy participants were scanned supine with the arm at full extension and at 30° and 60° elbow flexion. A log transform of the SWV was used as the response variable in the regression analysis, and the intraclass correlation coefficient was determined for reliability. The Shear Wave Velocity of the short head was lower than the long head on average. By fitting Bayesian mixed effect regression models to the data, the estimated posterior predictive mean velocities for the short head at full extension, 30°, and 60° were 3.14 m/s, 2.65 m/s, and 2.62 m/s, respectively; and 3.91 m/s, 3.02 m/s, and 3.15 m/s, respectively, for the long head of the biceps brachii. The intraclass correlation coefficients (0.64–0.92) were good to excellent. Shear Wave Elastography can detect the consistent difference in the stiffness of the two muscle bellies of the biceps brachii at multiple elbow angles. The assessment of muscle stiffness with Shear Wave Elastography should consider the morphology of the muscles.

Lateral rectus pulley concerning the orbital wall. Area of a stereotyped bony insertion

PurposeTo examine the lateral rectus muscle pulley and its bony insertion concerning the orbital rim and periorbita. DesignProspective. An observational anatomic study. MethodsStudy population: Twenty postmortem orbits (10 right, 10 left) of 10 Caucasian cadavers (8 females, 2 males; age range at death, 57–100 years; median age, 79.5 years) fixed by the Thiel method.Intervention: The floor of the temporal fossa was exposed, and a bone window on the lateral wall of the orbit, posterior to the sphenozygomatic suture, was created, keeping the periorbita intact. The lateral canthus and lateral palpebral ligament were isolated and opened, and the eyelids were folded back. The frontozygomatic suture was identified, and the orbital septum opened adjacent to the orbital rim. The conjunctiva was opened at the limbus, and the lateral rectus insertion was isolated. The bone pillar containing the frontozygomatic suture and the insertion of the periorbita and the pulley was isolated and removed en bloc. The lateral rectus muscle was isolated and excised.Main outcome measures: Position of the pulley ring on the lateral rectus muscle belly and its bony attachment area in the lateral wall of the orbit. ResultsThe pulley bony attachment was roughly quadrilateral with an approximate area of 90 mm2, 3 mm (mean, range 1–5 mm) posteroinferior to the frontozygomatic suture and 1 mm posterior to the orbital rim. The anterior margin of the pulley sleeve was found at 21.0 mm (median, p25-75 20.0–22.8) from the scleral insertion. ConclusionsThe lateral rectus pulley is stereotyped in its position in the muscle belly and its bony insertion, coinciding with the point of greatest adhesion of the periorbita to the anterior part of the lateral wall of the orbit.

Biomechanics Explains Variability of Response of Small Hypertropia to Graded Vertical Rectus Tenotomy

PurposeSmall angle hypertropia in sagging eye syndrome is conveniently treated by graded vertical rectus tenotomy, yet adjustable technique under topical anesthesia has been recommended due to variability of effect. We performed graded tenotomy in an experimental model to elucidate the effect reason for variability of response to this surgical procedure. DesignExperimental study: Methods: 32 fresh bovine rectus musculotendon specimens were prepared including continuity with insertional sclera, and extending for a total 40mm length to the proximal muscle bellies, and trimmed to 16mm width. Specimens were anchored by the clamps at the scleral insertion and muscle belly ends within a physiological chamber. After preconditioning and elongation to 10% strain was imposed by a linear motor, tensile force was allowed to stabilize at a plateau state. Then 25, 50, 75, 90, 100% marginal tenotomies were perormed progressively as remnant forces were measured. ResultsTendon thickness averaged 0.29±0.05mm and width 19.71±2.25mm. On average, remnant force decreased linearly (R2=0.985) from 4.23±1.34, 2.76±0.88, 1.70±0.73, 1.01±0.49, 0.39±0.10, and 0 N, at 0, 25, 50, 75, 90, 100% tenotomy. However, there was marked individual variability in effect among specimens, with coefficient of variation 32, 32, 43, 49, and 27%, respectively ConclusionOn average there is a linear relationship between graded rectus tenotomy and percentage force reduction, but the effect among individual tendons is large, paralleling the reported variation in surgical effect. This explains and implies continued advisability of adjustable technique in this procedure.

Effects of Transcutaneous Electrical Nerve Stimulation with Taping on Wrist Spasticity, Strength, and Upper Extremity Function in Patients with Stroke: A Randomized Control Trial.

Objective: Six months after the onset of stroke, over 60% of patients experience upper limb dysfunction, with spasticity being a major contributor alongside muscle weakness. This study investigated the effect of transcutaneous electrical nerve stimulation (TENS) with taping on wrist spasticity, strength, and upper extremity function in patients with stroke. Methods: In total, 40 patients with stroke were included and randomly divided into two groups: the TENS + taping (n = 20, age 52.4 ± 9.3 (range: 39 to 70)) and TENS (n = 20, age 53.5 ± 10.8 (range: 39 to 74)) groups. All subjects performed 30 sessions of task-related training, which included 10 min of postural control training and 20 min of task performance. Additionally, all subjects received TENS on the spastic muscle belly for 30 min before task-related training. In the TENS + taping group, taping was additionally applied to the forearm and wrist but not in the TENS group. The Modified Ashworth Scale was used to measure spasticity, and a handheld dynamometer was used to measure muscle strength. The Fugl-Meyer Assessment of Upper Extremity was used to evaluate the functional ability of the upper extremity. Results: In the TENS + taping group, spasticity and upper extremity function were significantly improved as compared to those in the TENS group (p < 0.05). However, no significant difference in muscle strength was observed between the two groups (p > 0.05). Conclusions: This study demonstrated that the combination of TENS and taping for spasticity and function of the upper extremity was more effective in relieving the spasticity than TENS alone. Therefore, we suggest this combination as an additional treatment for spasticity and function of the upper extremity.

Reappraisal of the morphological and morphometric study of the psoas minor muscle with clinical and developmental insights: cadaveric study.

The Psoas Minor (PMi) is the most unstable muscle of the psoas group of the posterior abdominal muscle. This muscle has a fusiform shape and consists of a short fusiform belly continuing distally as a long tendon inserted on the pecten pubis and the iliopectineal arch. The present study was conducted to obtain more detailed information about the muscle and to expand knowledge about its morphology and morphometry. The posterior abdominal wall of 30 adult cadavers was dissected. Anatomical variabilities in origin, insertion, length, width, and muscle-to-cone ratio were measured when PMi was found. The data collected was interpreted descriptively. PMi was found in 12 cases, ten bilateral and two unilateral. The origin was constant in all cases and, except for three cases, extended into the iliac fascia and the iliopubic eminence. Morphometric analysis revealed that the average length of the proximal muscle belly and distal tendons was 4.52 ± 1.35 cm and 13.05 ± 0.90 cm, respectively. The mean width of the muscle belly was 1.71 ± 0.17 cm, and that of the tendon was 0.47 ± 0.10 cm. On average, the muscle belly occupied the proximal 33.71 ± 6.15% of the total musculotendinous unit. Findings confirm the inconsistency of PMi in the study population. Morphological variations became more evident as the tendon approached the insertion level. The muscle's distal attachment to the iliac fascia may partially control the position, mechanical stability of the underlying iliopsoas and this circumstantial function may be clinically related to iliopsoas inflammation and pathology. However, further studies recommended to determine biomechanical validity and clinical applicability of this vestigial muscle in human.

Morphological study of the popliteus muscle-tendon complex in formalin embalmed adult cadavers

Background The dimensions of popliteus muscle and its tendon are subjected to variability in the origin, mode of insertion, innervation patterns and vascular supply. The aim of this study was to measure the length, thickness and width of the popliteus muscle and its tendon at its different parts. The objectives were to study the topographic anatomy of the neurovascular structures of the popliteus and also to determine the dimensions of the popliteo-fibular ligament. Methods This descriptive cross sectional institutional based study included 50 formalin embalmed adult lower limb specimens. The measurements were performed by using the digital Vernier caliper. Results The length of the popliteus muscle belly along the upper and lower border were 44.2±6.63 mm and 89.26±14.41 mm, width of the muscle belly at midpoint, musculotendinous junction and insertion were 28.45±6.85 mm, 11.7±3.5 mm and 75.95±10.7 mm. The thickness of muscle belly at the midpoint was 2.55±0.55 mm. The length of popliteal tendon, width at origin and at musculotendinous junction were 24.85±2.15 mm, 7.55±1.55 mm and 8.5±1.15 mm. The thickness of tendon of popliteus was 2.6±0.75 mm. The length of nerve to popliteus was 50.44±8.66 mm and its origin was located 27.54±6.18 mm from the intercondylar line. The distance of origin of medial and lateral geniculate arteries from the intercondylar line were 26.26±10.47 mm and 20.76±5.19 mm. The distance of division of popliteal artery was 49.44±16.26 mm from the intercondylar line. The length and width of the popliteo-fibular ligament was 17.84±3.43 mm and 7.36±1.9 mm individually. Conclusions This study offered detailed morphometric data of the popliteus and it is believed that the data of this anatomical research is enlightening to orthopedic surgeons particularly in the field of arthroscopic and plastic surgery. The data can be considered as the database from our population.

Internal joint stabilizer covered by an anconeus flap for elbow instability: surgical technique and preliminary results

BackgroundThe management of residual elbow instability is a challenge in both acute and chronic injuries. Hinged external fixators have been used but they are clumsy and associated to high rate of pin track complications. To address these issues, an internal joint stabilizer (IJS) was developed, but a subcutaneous frame may provide local tenderness and patients ‘complains. To improve the local comfort, the present study describes an alternative surgical approach in which the internal device is covered by the anconeus muscle becoming submuscular rather than subcutaneous as originally described. MethodsA prospective collection was performed of consecutive patients managed with an IJS (Skeletal Dynamics, Miami, FL, USA) as a temporary and additional stabilization for a residual elbow instability and covered by an anconeus flap. ResultsTen consecutive patients underwent IJS covered by an anconeus flap from January 2022, of whom eight with an acute injury and two suffering chronic injuries. At the mean follow-up of 13.5 months, all the patients had a stable elbow with a maintained concentric reduction. Successful results were achieved in terms of pain, ROM and clinical outcomes. All patients underwent removal surgery at an average of 5.5 months without any local discomfort or complains. The device removal required a small anconeus elevation which appeared of good quality in each patient analyzed. ConclusionThe IJS represents an effective and reliable option as a temporary stabilization for residual elbow instability. When performing a lateral approach with an anconeus flap, the internal device can be completely covered by the muscle belly at the end of the procedure. The preliminary results suggest at least similar tolerance and patient ‘satisfaction without any relevant increase in complication rare.

Morphological variability of the pectoralis minor muscle. Study in human fetuses

BackgroundThe pectoralis minor muscle is located in the anterior thoracic wall. Typically, is constituted by a single belly originating from the 3rd to the 5th rib and inserted into the coracoid process near the origins of the biceps brachii shorth head and of the coracobrachialis muscle. The current study, on human fetuses, aims to detect all morphological muscle variants and to create a new classification system. Material and methodsClassical dissection of the thoracic wall and the upper limb was bilaterally performed on 25 (13 male and 12 female) human formalin-fixed fetuses aged 18–38 weeks of gestation. The spontaneously aborted fetuses were donated after parental consent to the Medical University anatomy program. The pectoralis minor muscle’s morphology, the number of the muscle’s bellies, their origins, and insertions, as well as the morphometric details of each belly of the pectoralis minor, were assessed. ResultsThe pectoralis minor was bilaterally found in all fetuses (50 cases). Three types of muscle were identified based on the number of muscle bellies. In type, I (typical anatomy), were classified the cases with a single belly (in 66%). This type was divided into two subtypes (Ia and Ib). In the subtype Ia, the single belly had a typical course, and in Ib, a proximal attachment was characterized by two small bellies connecting together and creating one muscular mass. In type II, two bellies (24%), and in type III, three bellies (10%) were identified. ConclusionsPectoralis minor is morphologically variable in the number of its bellies, its course, its origins, its insertions, and the location of its proximal attachments. The most common type (typical anatomy) was the type I represented by one belly. Other identified variants in the number of bellies by the present study may be hypothetically a result of prematurely terminated embryogenesis.

Effects of photobiomodulation therapy on muscle function in individuals with multiple sclerosis

BackgroundIn people with multiple sclerosis (pwMS), muscle fatigue and weakness are common issues that can interfere with daily activities. Photobiomodulation therapy (PBMT), comprising light in a 600–1100 nm bandwidth, is a low-level laser therapy thought to improve muscle performance in non-disease populations, in part, by improving mitochondrial function and thus, might be beneficial in pwMS. Given this potential, we aimed to investigate the effects of PBMT on muscle performance in pwMS, both in the short-term and over an extended period. MethodsThis study consisted of two parts with a randomized double-blind crossover design. In study I, muscle function was assessed in four sessions before and after PBMT in ambulatory pwMS (N = 17, F = 14) as follows: maximal voluntary contraction (MVC) and muscle fatigue of the right tibialis anterior (TA) muscle was compared at baseline and following a two-min submaximal fatiguing contraction. Then, PBMT was administered to the belly of TA muscle at different doses of energy of an active device (40 J, 80 J, 120 J) or placebo. The muscle function assessment was then repeated. Outcome variables: muscle force recovery (%), muscle fatigue (%). Statistical tests included McNemar's exact test, Wilcoxon signed-rank test, and the Friedman test. In study II, a subgroup from study I (N = 12, F = 11) received individualized doses (i.e., best dose-effect observed in study I) of active, or placebo PBMT, which was administered on the TA muscle for two weeks. Muscle function assessments were performed pre- and post-PBMT in four sessions similar to study I. Outcome variables: Baseline strength (N), endurance time (s), and muscle fatigue (%). The Wilcoxon signed-rank test was used for statistical analysis. Values are reported as mean (SD). ResultsIn study I, participants who received a high dose of PBMT showed significant improvement in force recovery (101.89 % (13.55 %)) compared to the placebo group (96.3 % (18.48 %); p = 0.03). Muscle fatigue did not significantly improve with either active PBMT or placebo. In study II, active PBMT resulted in a significant improvement in muscle strength compared to both the baseline (pre-PBMT = 162.70 N (37.52 N); post-PBMT = 185.56 N (33.95 N); p = 0.01) and the placebo group (active PBMT: mean-change = 22.87 N (23.67 N); placebo: mean-change = −4.12 N (31.95 N); p = 0.02). Endurance time and muscle fatigue did not show significant improvement with either active PBMT or placebo. ConclusionOur findings suggest that an individualized dose of PBMT might improve muscle performance, including force recovery and strength in individuals with mild-moderate MS. Therefore, PBMT might be a novel therapeutic modality, either as a standalone treatment or in combination with other interventions, to improve muscle performance in pwMS.

Comparison of the activation level in the sensorimotor cortex between motor point and proximal nerve bundle electrical stimulation

Objective. Neuromuscular electrical stimulation (NMES) is widely used for motor function rehabilitation in stroke survivors. Compared with the conventional motor point (MP) stimulation, the stimulation at the proximal segment of the peripheral nerve (PN) bundles has been demonstrated to have multiple advantages. However, it is not known yet whether the PN stimulation can increase the cortical activation level, which is crucial for motor function rehabilitation. Approach. The current stimuli were delivered transcutaneously at the muscle belly of the finger flexors and the proximal segment of the median and ulnar nerves, respectively for the MP and PN stimulation. The stimulation intensity was determined to elicit the same contraction levels between the two stimulation methods in 18 healthy individuals and a stroke patient. The functional near-infrared spectroscopy and the electromyogram were recorded to compare the activation pattern of the sensorimotor regions and the target muscles. Main Results. For the healthy subjects, the PN stimulation induced significantly increased concentration of the oxygenated hemoglobin in the contralateral sensorimotor areas, and enhanced the functional connectivity between brain regions compared with the MP stimulation. Meanwhile, the compound action potentials had a smaller amplitude and the H-reflex became stronger under the PN stimulation, indicating that more sensory axons were activated in the PN stimulation. For the stroke patient, the PN stimulation can elicit finger forces and induce activation of both the contralateral and ipsilateral motor cortex. Conclusions. Compared with the MP stimulation, the PN stimulation can induce more cortical activation in the contralateral sensorimotor areas possibly via involving more activities in the central pathway. Significance. This study demonstrated the potential of the PN stimulation to facilitate functional recovery via increasing the cortical activation level, which may help to improve the outcome of the NMES-based rehabilitation for motor function recovery after stroke.

Double Chin Concerns afterEn Bloc Mandibular U-ShapedOsteotomy: Submental-Cervical Soft Tissue Changes and Anterior Belly of Digastric Muscle Assessment.

To assess submental-cervical soft tissue changes afteren bloc mandibularU-shapedosteotomy and examine alterations in the anterior belly of digastric muscle (ABDM). A retrospective study analyzed 20 patients who underwent en bloc mandibularU-shaped osteotomy from 2018 to 2023. Preoperative (Tp) and long-term follow-up (Tf) CT data were collected for analysis, measuring mandibular volume, soft tissue thickness at menton (Mes) and cervicale (C), and ABDM parameters (length, cross-sectional area (CSA), volume, distance from centroid point to the mandibular margin). Correlation analyses were performed to investigate the connection between soft tissue thicknesschanges, ABDM changes, and mandibular osteotomy volume. Long-term follow-up revealed a significant increase in soft tissue thickness at the Mes and C points after U-shaped mandibular osteotomy, especially at the C point. The adaptive length of ABDM decreased, CSA increased, and volume decreased, but the ABDM centroid point shifted downward relative to the mandibular margin, indicating drooping protrusion. The increment of soft tissue thicknesswas moderately positively correlated with the amount of osteotomy, and the decrement of ABDMlength and volume were slightly positively correlated with the amount of osteotomy. The degree of soft tissue relaxation afterU-shaped osteotomy is related to the extent of osteotomy. Notably, the protrusion of ABDM relative to the mandibular margin affects submental-cervical contour aesthetics. Prior to U-shaped osteotomy, it is crucial to assess the soft tissue condition of the patient's lower face, and the individualized design of the osteotomy volume should be carried out cautiously and safely. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Closed Midsubstance Rupture of the Biceps Brachii and Brachialis: A Case Report

Closed rupture of the biceps brachii muscle belly should be considered in patients who experience arm pain and weakness after a forceful extension of the elbow against a fixed point of compression in the mid-arm. A delayed or missed diagnosis may portend inferior outcomes. Magnetic resonance imaging (MRI) can confirm the diagnosis but may not fully define the lesion. Therefore, the treating physician should be fully prepared to encounter a greater magnitude of muscular injury than that defined by the MRI. In young, active patients, early surgical repair can be considered to optimize the strength and cosmetic appearance of the limb. The repair technique should consist of a self-grasping suture technique, which may need to be augmented by fascial flaps or allograft tissue.