Hamstring to quadriceps strength ratio and cross-sectional area of the quadriceps and hamstrings muscles assessed using extended field-of-view ultrasonography

Thigh muscle mass evaluated by point-of-care ultrasound is associated with short-term mortality in patients with sepsis in the emergency department

Muscle mass depletion is associated with mortality and morbidity in various conditions including sepsis. However, few studies have evaluated muscle mass using point-of-care ultrasound in patients with sepsis. This study aimed to evaluate the association between thigh muscle mass, evaluated using point-of-care ultrasound with panoramic view in patients with sepsis in the emergency department, and mortality. From March 2021 to October 2022, this prospective observational study used sepsis registry. Adult patients who were diagnosed with sepsis at the emergency department and who underwent point-of-care ultrasounds for lower extremities were included. The thigh muscle mass was evaluated by the cross-sectional area of the quadriceps femoris (CSA-QF) on point-of-care ultrasound using panoramic view. The primary outcome was 28 day mortality. Multivariable Cox proportional hazard model was performed. Of 112 included patients with sepsis, mean CSA-QF was significantly lower in the non-surviving group than surviving group (49.6 [34.3-56.5] vs. 63.2 [46.9-79.6] cm2, p = 0.002). Each cm2 increase of mean CSA-QF was independently associated with decreased 28 day mortality (adjusted hazard ratio 0.961, 95% CI 0.928-0.995, p = 0.026) after adjustment for potential confounders. The result of other measurements of CSA-QF were similar. The muscle mass of the quadriceps femoris evaluated using point-of-care ultrasound with panoramic view was associated with mortality in patients with sepsis. It might be a promising tool for determining risk factors for mortality in sepsis patients in the early stages of emergency department.

Design and validation of a wearable dynamometry system for knee extension-flexion torque measurement

Muscle strength assessments are vital in rehabilitation, orthopedics, and sports medicine. However, current methods used in clinical settings, such as manual muscle testing and hand-held dynamometers, often lack reliability, and isokinetic dynamometers (IKD), while reliable, are not easily portable. The aim of this study was to design and validate a wearable dynamometry system with high accessibility, accuracy, and reliability, and to validate the device. Therefore, we designed a wearable dynamometry system (WDS) equipped with knee joint torque sensors. To validate this WDS, we measured knee extension and flexion strength in 39 healthy adults using both the IKD and WDS. Comparing maximal isometric torque measurements, WDS and IKD showed strong correlation and good reliability for extension (Pearson's r: 0.900; intraclass correlation coefficient [ICC]: 0.893; standard error of measurement [SEM]: 9.85%; minimal detectable change [MDC]: 27.31%) and flexion (Pearson's r: 0.870; ICC: 0.857; SEM: 11.93%; MDC: 33.07%). WDS demonstrated excellent inter-rater (Pearson's r: 0.990; ICC: 0.993; SEM: 4.05%) and test-retest (Pearson's r: 0.970; ICC: 0.984; SEM: 6.15%) reliability during extension/flexion. User feedback from 35 participants, including healthcare professionals, underscores WDS's positive user experience and clinical potential. The proposed WDS is a suitable alternative to IKD, providing high accuracy, reliability, and potentially greater accessibility.

Distal hamstrings tendons mechanical properties at rest and contraction using free-hand 3-D ultrasonography

Tendon properties impact human locomotion, influencing sports performance, and injury prevention. Hamstrings play a crucial role in sprinting, particularly the biceps femoris long head (BFlh), which is prone to frequent injuries. It remains uncertain if BFlh exhibits distinct mechanical properties compared to other hamstring muscles. This study utilized free-hand three-dimensional ultrasound to assess morphological and mechanical properties of distal hamstrings tendons in 15 men. Scans were taken in prone position, with hip and knee extended, at rest and during 20%, 40%, 60%, and 80% of maximal voluntary isometric contraction of the knee flexors. Tendon length, volume, cross-sectional area (CSA), and anteroposterior (AP) and mediolateral (ML) widths were quantified at three locations. Longitudinal and transverse deformations, stiffness, strain, and stress were estimated. The ST had the greatest tendon strain and the lowest stiffness as well as the highest CSA and AP and ML width strain compared to other tendons. Biceps femoris short head (BFsh) exhibited the least strain, AP and ML deformation. Further, BFlh displayed the highest stiffness and stress, and BFsh had the lowest stress. Additionally, deformation varied by region, with the proximal site showing generally the lowest CSA strain. Distal tendon mechanical properties differed among the hamstring muscles during isometric knee flexions. In contrast to other bi-articular hamstrings, the BFlh high stiffness and stress may result in greater energy absorption by its muscle fascicles, rather than the distal tendon, during late swing in sprinting. This could partly account for the increased incidence of hamstring injuries in this muscle.

Electrical impedance myography combined with quantitative assessment techniques in paretic muscle of stroke survivors: Insights and challenges

Aging is a non-modifiable risk factor for stroke and the global burden of stroke is continuing to increase due to the aging society. Muscle dysfunction, common sequela of stroke, has long been of research interests. Therefore, how to accurately assess muscle function is particularly important. Electrical impedance myography (EIM) has proven to be feasible to assess muscle impairment in patients with stroke in terms of micro structures, such as muscle membrane integrity, extracellular and intracellular fluids. However, EIM alone is not sufficient to assess muscle function comprehensively given the complex contributors to paretic muscle after an insult. This article discusses the potential to combine EIM and other common quantitative methods as ways to improve the assessment of muscle function in stroke survivors. Clinically, these combined assessments provide not only a distinct advantage for greater accuracy of muscle assessment through cross-validation, but also the physiological explanation on muscle dysfunction at the micro level. Different combinations of assessments are discussed with insights for different purposes. The assessments of morphological, mechanical and contractile properties combined with EIM are focused since changes in muscle structures, tone and strength directly reflect the muscle function of stroke survivors. With advances in computational technology, finite element model and machine learning model that incorporate multi-modal evaluation parameters to enable the establishment of predictive or diagnostic model will be the next step forward to assess muscle function for individual with stroke.

Hamstring Muscle Quality Properties Using Texture Analysis of Ultrasound Images

The aim of this study was to examine the intra- and inter-muscular differences of the hamstring muscles using textural analysis of ultrasound (US) images, and the relationship between textural indicators with hamstring torque. Transverse US scans were obtained from 10 young males from four different measurement sites along the thigh of each individual hamstring muscle at rest. Maximum-knee-flexion isometric torque measurements were also obtained. Texture analysis was applied to US images, and five gray-level co-occurrence matrix (GLCM) features were quantified: entropy (ENT), angular second moment (ASM), inverse difference moment (IDM), contrast (CON) and correlation (COR). The intraclass correlation coefficients ranged from 0.77 to 0.99, and the standard error of measurement ranged from 0.06 to 10.05%, indicating high test-retest reliability. Analysis of the variance indicated significant differences between measurement sites and individual muscles, with the proximal measurement sites having greater values for ASM, IDM and COR and lower values for ENT and CON compared with the distal sites. Additionally, only the COR at the proximal measurement site exhibited a significant relationship (r = -0.66) with strength. The present study indicated significant differences among hamstrings and measurement locations with respect to the textural analysis and may provide a novel indicator of hamstring functional properties.

Anatomy, Morphology and Function of the Tensor of Vastus Intermedius: A Systematic Review

The tensor of vastus intermedius is a newly discovered muscle that is located at the anterior compartment of the thigh. The aim of the present study is to report, assess and synthetize the existing evidence on the anatomy, variation and morphological characteristics of the TVI as well as to examine its clinical importance. A systematic review was performed evaluating both anatomical and medical imaging studies which provided information about TVI anatomy, prevalence, variations and morphological characteristics. The search strategy was conducted in major electronic databases. Two reviewers worked independently to screen all possible references via a title/abstract examination. Methodological quality was examined with the Anatomical Quality Assurance checklist. A total of 295 cadaveric knees were included in the nine studies where in 244 (82.7%) cases the TVI was identified. Based on this evidence, it appears that the TVI is located between the vastus lateralis and vastus intermedius. The muscle belly is located proximally, and it is combined with a broad and flat aponeurosis before forming a tendinous structure that is attached at the medial aspect of the patella. The TVI presented some morphological variations and complex muscle architecture that varied along its length. There is insufficient good quality evidence as more than half of the included studies were ranked as having a "High" risk of bias with various methodological issues. Higher quality studies are recommended to evaluate the TVI morphology to better understand its functional and clinical importance.

Reliability of Distal Hamstring Tendon Length and Cross-sectional Area Using 3-D Freehand Ultrasound

The objective of this study was to investigate the reliability of distal hamstring tendon morphology using freehand 3-D ultrasound (US). Freehand 3-D US scans were acquired for 16 young males and females, in two sessions, spaced a week apart. The length, volume, cross-sectional area (CSA) and echo intensity (EI) of the semitendinosus (ST), biceps femoris long and short head and semimembranosus (SM) tendons were acquired. Measurements of the CSA and EI were obtained from three sites along each tendon. The intra-class correlation coefficients ranged from 0.88-0.99 of the examined variables, indicating high test-retest reliability. In addition, the minimal detectable change (MDC) ranged from 0.255-3.766 mm (MDC% of the mean: 0.406%-12.558%) for hamstring tendon length, from 0.036-0.077 mL (MDC%: 1.548%-3.178%) for tendon volume, from 0.512-1.948 mm² (MDC%: 0.702%-3.586%) for CSA and from 0.898-2.586 au (MDC%: 1.145%-3.325%) for EI. Of the four hamstring tendons, ST had the greatest length (141.587 ± 10.701 mm) and EI (94.637 ± 5.536 au), while SM had the greatest volume (3.056 ± 0.421 mL) and CSA (115.277 ± 16.442 mm²) relative to other tendons. Freehand 3-D US appears to be a reliable tool for the evaluation of hamstring distal tendon morphology; hence, its use for in vivo evaluation of tendon properties is promising.

Muscle- and Region-Specific Associations Between Muscle Size and Muscular Strength During Hip Extension and Knee Flexion in the Hamstrings

CONTEXT

Strength deficits of the hamstrings following sports injuries decrease athletic performance and increase the risk of injury recurrence. Previous studies have shown a high correlation between the muscular strength during hip-extension and knee-flexion and total muscle size of the hamstrings. However, it remains unclear which region of the individual hamstring muscles is closely associated with muscular strength.

OBJECTIVE

To investigate the relationship between the size of each region of the individual hamstring muscles and muscular strength during hip extension and knee flexion.

DESIGN

Within-subject repeated measures.

SETTING

University laboratory.

PARTICIPANTS

Twenty healthy young male volunteers who regularly engaged in sports activities.

OUTCOME MEASURES

Anatomical cross-sectional areas were acquired from the proximal, middle, and distal regions of the biceps femoris long head, biceps femoris short head, semitendinosus, and semimembranosus. Hip-extension and knee-flexion strength were measured during maximal voluntary isometric and concentric contractions (angular velocities of 60°/s and 180°/s).

RESULTS

The anatomical cross-sectional area of the distal regions in biceps femoris long head (r = .525-.642) and semitendinosus (r = .567) were significantly correlated with hip-extension strength under all conditions and only at an angular velocity of 180°/s, respectively. Meanwhile, anatomical cross-sectional areas of the distal regions in biceps femoris short head (r = .587-.684) and semimembranosus (r = .569-.576) were closely associated with knee-flexion strength under all conditions.

CONCLUSION

These results suggest that muscle size in the distal regions of biceps femoris long head and semitendinosus greatly contributes to the production of hip-extension strength, whereas that of biceps femoris short head and semimembranosus significantly contributes to the generation of knee-flexion strength. These findings could be useful for designing training and rehabilitation programs to efficiently improve strength deficits following sports injuries such as strain injury and anterior cruciate ligament tears.

Assessment of muscle volume using magnetic resonance imaging (MRI) in football players after hamstring injuries

Muscle injuries of the hamstrings are among the most frequent in football and a main cause for significant time away from training and competition. The purpose of this study was to prospectively evaluate the loss of muscle volume in recreational football players three and six weeks after initial trauma. We hypothesized that significant muscle volume loss occurs within 6 weeks after the initial injury event. Twenty recreational football players (mean-age=25 ± 4years; mean-height=181 ± 8cm; mean-weight=81 ± 10kg) with type3a (minor partial muscle tear) and type3b (moderate partial muscle tear) injuries were included. Muscle volume was determined using established methods for the hamstrings and the quadriceps femoris muscle within 3 days and after 3 and 6 weeks following the initial injury. The injured hamstrings lost 6.5% (mean=64 cm³(95%CI=31-98 cm³), p<0.001), the healthy hamstrings lost 2.1% (mean=21 cm³(3-44 cm³),p=0.096) of muscle volume after six weeks. The quadriceps in the injured leg lost 3.8% (mean=78 cm³(51-104 cm³), p<0.001) and 4.5% (83 cm³ (45-121 cm³), p<0.001) in the healthy leg. Muscle volume loss inversely correlated with activity levels in the healthy leg for the quadriceps (r=0.96 (0.90-0.98); R²=0.92; p<0.001) and the hamstrings (r=0.72 (0.40-0.88); R²=0.51; p<0.001), as well as the quadriceps in the injured leg (r=0.70 (0.37-0.87); R²=0.49; p<0.001), but not the injured hamstrings. Muscle volume ratio of hamstrings to quadriceps in the control limb was 0.52 ± 0.06 and 0.53 ± 0.06 in the injured leg. The rehabilitation period of six weeks did not have a relevant negative or a positive effect on ratios. Significant muscle volume loss in the upper thigh occurs in recreational soccer players within three, and within six weeks after a hamstring injury and lies between 2% and 7%.Highlights This study found that significant muscle volume loss occurs within six weeks after sustaining hamstring muscle group injuries.Additionally, most of the non-professional football players in the present study demonstrated low hamstring-to-quadriceps volume ratios in both the injured, as well as the heathy leg. Low hamstring-to-quadriceps volume ratios may provide an opportunity to focus on muscle hypertrophy strategies to help reduce the risk for muscle imbalances and thus future injury.After three weeks of resting, reduced training activity, compared to the training activity before the injury, seems to be sufficient to preserve 99% of the remaining muscle volume in the quadriceps and as well as the healthy hamstrings. The number of training-minutes correlates statistically significant inversely with the muscle volume lost in a rehabilitation period.

Extended field-of-view ultrasound imaging is reliable for measuring Transversus Abdominis muscle size at rest and during contraction

Background

The strength and size of core muscles, including the abdominal muscles, are crucial to proper function in most activities. Therefore, it is important to reliably assess these characteristics. Our primary objective was to determine if the length, thickness and cross-sectional area of the transversus abdominis (TrA) can be visualized independently from the internal and external abdominal oblique muscles using extended field of view ultrasound imaging at rest and with contraction and to establish its intra- and inter-tester reliability.

Methods

Twenty-six individuals were recruited to participate in the study (20 F, 6 M), average age 24.0 years (SD 9.4), height 170.7 cm (SD 8.6) and weight 63.9 kg (SD 9.0). From this total number of participants, two groups of 16 randomly selected participants were assessed to determine intra- and inter-tester reliability respectively. Extended field of view ultrasound images were obtained at three vertebral levels during rest and contraction in the side lying position for both the right and left sides of the trunk.

Results

Excellent intra-tester and inter-tester reliability was seen (ICC range of 0.972 to 0.984). The overall average percent standard error of the measurement for all measurements and locations was approximately 4%. The overall average minimal difference for the thickness measurement for the resting and contraction conditions combined were as follows: intratester 0.056 (0.014) cm and intertester 0.054 (0.017) cm, for area intratester 0.287 (0.086) cm² and intertester 0.289 (0.101) cm² and for length intratester 0.519 (0.097) cm and intertester 0.507 (0.085) cm.

Conclusions

Extended field of view ultrasound imaging is an effective method of reliably capturing clear images of the TrA during rest and contraction. It provides an efficient mechanism for the analysis of muscle morphology by being able to measure the cross-sectional area, thickness, and length on one image. This methodology is recommended for studies investigating TrA function and training.