Regional variations and sex-related differences of stiffness in human tracheal ligaments.

Purpose: There have been numerous studies focused on the stiffness of tracheal cartilage. However, no research has been conducted specifically on the annular ligament, nor have any regional differences in the annular ligament been identified. The purpose of this study was to investigate the stiffness of the ligaments present between the thyroid, cricoid and tracheal cartilages.

Variation in the origin of the plantar aponeurosis and its relationship to the origin of the abductor hallucis muscle.

The plantar aponeurosis comprises medial, central, and lateral bands, which arise from the calcaneal tuberosity. Descriptions of the origin of the abductor hallucis vary among different textbooks. The central band and abductor hallucis muscles are related to the windlass mechanism.

Assessing site-specificity of the biomechanical properties of hamstring aponeuroses using MyotonPRO: A cadaveric study.

Background: Hamstring muscles are the most frequently reported sites of muscle strain injuries, especially near the bi-articular muscles' myotendinous junction, where aponeurosis provides a connective tissue network linking muscle fibers to the tendon. This study aimed to investigate the reliability and site-specific differences of hamstring aponeuroses under different conditions (formalin and urea) using MyotonPRO.

Methods: Eight hamstring muscle groups were dissected from four human cadavers (two males and two females) aged 83-93 years.

Time-varying and speed-matched model for the evaluation of stroke-induced changes in ankle mechanics.

The ankle mechanics (stiffness and moment) are modulated continuously when interacting with the environment during human walking. However, it remains unclear how ankle mechanics vary with walking speeds, and how they are affected by stroke. This study aimed to determine time-varying ankle stiffness and moment in stroke participants during walking, comparing them with healthy participants at matched speeds.

Biomechanical assessment of gastrocnemii and Achilles tendon using MyotonPRO: measurements, and preliminary measurements using formalin-fixed tissues.

Purpose: This study aims to evaluate the reliability and validity of using MyotonPRO to quantify the mechanical properties of the muscle-tendon unit through in vivo measurements and preliminary in situ measurements using formalin-fixed tissues.

Materials And Methods: The mechanical properties of gastrocnemii and the Achilles tendon of 12 healthy adults (six males and six females, 34.9 ± 5.

Fatigue-induced changes in hamstrings' active muscle stiffness: effect of contraction type and implications for strain injuries.

Purpose: Hamstring strain injuries may occur due to differential fatigue and compromised mechanical properties among the hamstring muscles. We examined (1) the effect of fatigue on hamstrings active muscle stiffness, and (2) whether contraction type affects active muscle stiffness changes during a submaximal fatiguing task.

Methods: Nine healthy males completed 99 submaximal knee flexions in isometric (ISO), concentric (CON), and eccentric (ECC) conditions.

Relationship between attachment site of tibialis anterior muscle and shape of tibia: anatomical study of cadavers.

Background: Tibialis anterior (TA) muscle is the largest dorsiflexor of the ankle joint and plays an important role during gait movement. However, descriptions of the TA attachment site are inconsistent even among major anatomy textbooks, and its origin, especially the attachment site for the tibia, has not been reported in detail. This study is the first experimental attempt to investigate the origin of the TA in detail, paying particular attention to the relationship with the shape of the tibia, including sex differences.

Investigation of the association between human fascia lata thickness and its neighboring tissues' morphology and function using B-mode ultrasonography.

The fascia lata is a membrane tissue which envelopes all thigh muscles and connects with the subcutaneous adipose tissues through loose connective tissues. It is presumable that the morphology of the fascia lata is strongly affected by the unique properties of underlying thigh muscles and subcutaneous adipose tissues. We aimed to investigate the relationships between characteristics of the fascia lata and adjoining adipose tissues and underlying muscles.

Hamstrings load bearing in different contraction types and intensities: A shear-wave and B-mode ultrasonographic study.

The main aim was to examine the load bearing of individual hamstring muscles in different contraction types and intensities, through local stiffness measurement by shear wave elastography (SWE). A secondary aim was to examine the relationship between the SWE stiffness measure and hamstrings morphology. Ten healthy males (age 22.

Inhomogeneous and anisotropic mechanical properties of the triceps surae muscles and aponeuroses in vivo during submaximal muscle contraction.

This study aimed to identify characteristics of the triceps surae muscles and aponeuroses stiffness in vivo, during graded isometric submaximal plantarflexion efforts. A total of twelve healthy male subjects (age: 27 ± 4 years) participated and were required to stay at rest (0% MVC) and perform isometric submaximal plantar flexion contractions (20%, 40%, 60% of MVC) on a dynamometer. Young's modulus of triceps surae muscles and the adjoining aponeuroses between gastrocnemii and soleus at the proximal and distal sites were obtained in the longitudinal direction (along muscle's line of action) during at rest and submaximal plantar flexions.

The Effects of Extracorporeal Shock Wave Therapy on Spastic Muscle of the Wrist Joint in Stroke Survivors: Evidence From Neuromechanical Analysis.

This study combined neuromechanical modeling analysis, muscle tone measurement from mechanical indentation and electrical impedance myography to assess the neural and peripheral contribution to spasticity post stroke at wrist joint. It also investigated the training effects and explored the underlying mechanism of radial extracorporeal shock wave (rESW) on spasticity. People with first occurrence of stroke were randomly allocated to rESW intervention or control group.

Inhomogeneous and Anisotropic Mechanical Properties of the Triceps Surae Aponeuroses in Older Adults: Relationships With Muscle Strength and Walking Performance.

This study investigated (a) site- and direction-dependent variations of passive triceps surae aponeurosis stiffness and (b) the relationships between aponeurosis stiffness and muscle strength and walking performance in older individuals. Seventy-nine healthy older adults participated in this study. Shear wave velocities of the triceps surae aponeuroses at different sites and in two orthogonal directions were obtained in a prone position at rest using supersonic shear imaging.

Site dependent elastic property of human iliotibial band and the effect of hip and knee joint angle configuration.

The iliotibial band (ITB) is the lateral thickening of the fascia lata. The ITB has been extensively studied for its relevance to injury, but not much is known about its elastic properties. We aimed to investigate the site- and joint angle-dependence of ITB elasticity.

Dependence of muscle and deep fascia stiffness on the contraction levels of the quadriceps: An in vivo supersonic shear-imaging study.

In the present study we investigated muscle contraction-driven changes in deep fascia mechanical property, to reveal mechanical interactions between them. Fourteen males (22-37 yr) performed isometric knee extension at 20, 40, 60% of the maximal voluntary contraction (MVC). During each contraction and at rest, shear wave velocities (SWV) of the rectus femoris (RF) and vastus lateralis (VL) and fascia lata were measured in both longitudinal and transverse ultrasound transducer directions relative to the thigh.

Morphological and mechanical properties of the human triceps surae aponeuroses taken from elderly cadavers: Implications for muscle-tendon interactions.

The human triceps surae (two gastrocnemii and soleus) has aponeuroses in the proximal and distal aspects, the latter of which insert into the calcaneus by sharing the common Achilles tendon. These tendinous tissues are known to have elasticity and upon muscle contraction the aponeurosis is stretched both longitudinally (along the muscle's line of action) and transversely. Higher aponeurosis transverse deformability has been documented, but there is a paucity of information on the morphology and mechanical properties of human aponeurosis.

Neuromuscular Adaptations to Work-matched Maximal Eccentric versus Concentric Training.

Unlabelled: It is unclear whether the superiority of eccentric over concentric training on neuromuscular improvements is due to higher torque (mechanical loading) achievable during eccentric contractions or due to resulting greater total work.

Purpose: This study aimed to examine neuromuscular adaptations after maximal eccentric versus concentric training matched for total work.

Methods: Twelve males conducted single-joint isokinetic (180°·s) maximal eccentric contractions of the knee extensors in one leg (ECC-leg) and concentric in the other (CON-leg), 6 sets per session (3-5 sets in the initial 1-3 sessions), 2 sessions per week for 10 wk.