Characteristics of ulnohumeral joint alignment in distal ulnar collateral ligament tears compared to proximal tears in baseball and softball players.

Background: Dysfunctional features of distal ulnar collateral ligament (UCL) tears remain unclear. We aimed to clarify the characteristics of valgus and rotational alignment of the ulnohumeral joint at rest in distal UCL tears compared with those in proximal tears.

Methods: The participants were baseball and softball players diagnosed with UCL tears, classified as proximal, middle, or distal.

Spine Alignment in Standing and Maximal Upper Limb Elevation in Baseball Players with Lumbar Spondylolysis and Those without Low Back Pain.

The changes in lumbar lordosis angle (LL) and sacral slope angle (SS) related to upper limb elevation and thoracic kyphosis angle (TK) in baseball players with spondylolysis remain unclear. Herein, we investigated baseball players with spondylolysis and those without low back pain, comparing LL and SS with upper limb elevation within and between groups and TK between groups. Baseball players with spondylolysis were enrolled as subjects, and baseball players without low back pain were enrolled as controls (n = 8 each).

Comparison of alignment and spondylolysis fracture angle in bilateral and unilateral spondylolysis.

Objectives: Spondylolysis occurs bilaterally or unilaterally and bilateral spondylolysis increases the risk of developing isthmic spondylolisthesis. The characteristics of the lumbar lordosis angle (LLA), sacral slope angle (SSA), and spondylolysis fracture angle (SFA) in bilateral spondylolysis compared with those in unilateral spondylolysis have not been clarified. The purpose of this study was to compare the LLA, SSA, and SFA of bilateral and unilateral spondylolysis.

Motion Analysis Focusing on Rotational Movements of Professional Female Baseball Pitchers: Comparison with Male University Baseball Pitchers.

Purpose: The purpose of this study was to compare pitching motion of the professional female baseball pitchers with the male university baseball pitchers focused on the pelvic and thoracic movements.

Subjects And Methods: The participants were 15 healthy professional female baseball pitchers (11 right-handers and 4 left-handers; age, 21.7 ± 3.

Changes in Medial Elbow Joint Space When Elbow Valgus Stress Is Applied at Different Limb Positions and Loads In Vivo.

Background: Ulnar collateral ligament (UCL) injury is a common sports injury among overhead-throwing athletes and causes medial elbow pain and instability. UCL injury is generally diagnosed based on symptoms, physical findings, and image evaluation. To standardize the method for evaluating elbow valgus instability, more information is needed regarding changes in the medial elbow joint space (JS) in healthy elbows.

Influence of Continuous Elbow Valgus Stress on the Medial Elbow Joint Space.

Background: To investigate the effect of ulnar collateral ligament stretching due to the "creep phenomenon," the effect of accumulating elbow valgus stress on ligaments must be clarified.

Purpose: To evaluate the effect of continuous elbow valgus stress on the medial elbow joint space (JS).

Study Design: Controlled laboratory study.

Elbow valgus stability of the transverse bundle of the ulnar collateral ligament.

Background: The purpose of this study was to clarify elbow valgus stability of the transverse bundle (TB). We hypothesized that the transverse bundle is involved in elbow valgus stability.

Methods: Twelve elbows of six Japanese Thiel-embalmed cadavers were evaluated.

Contributions of the Third and Fourth Digits and the Second and Fifth Digits of the Flexor Digitorum Superficialis Muscle to Elbow Valgus Stability.

Background: Thiel cadavers have been reported to have lifelike flexibility and mechanical properties, but whether they are useful for measurement of the ulnohumeral joint space (JS) is unclear. The contributions of the third and fourth digits and the second and fifth digits of the flexor digitorum superficialis (FDS) to elbow valgus stability are also unknown.

Purpose: To (1) clarify whether Thiel cadavers can be used for JS measurement on ultrasound and (2) identify the contributions to valgus stability of the third and fourth digits and the second and fifth digits of the FDS.

Relationship between morphology of transverse bundle of ulnar collateral ligament and adjacent tissues.

Purpose: The purpose of this study was to clarify the incidence of the transverse bundle (TB) of the ulnar collateral ligament (UCL), the relationships between TB morphology and morphology of the anterior bundle (AB) or posterior bundle (PB) of the UCL, and the relationship between the TB and the posterior common tendon (PCT).

Methods: This study examined 38 elbows from 23 cadavers. TB, AB, and PB were classified morphologically.

Relationship Between Anterior Knee Laxity and General Joint Laxity During the Menstrual Cycle.

Background: Anterior cruciate ligament (ACL) injury has been reported to have a higher incidence in women than in men.

Purpose/hypothesis: The purpose was to examine the relationship of anterior knee laxity (AKL), stiffness, and generalized joint laxity (GJL) with respect to the menstrual cycle. It was hypothesized that AKL and GJL would increase during the ovulation phase, when estrogen levels are high.

A preliminary study exploring the change in ankle joint laxity and general joint laxity during the menstrual cycle in cis women.

Background: The purpose of the present study was to examine the relationship between ankle joint laxity and general joint laxity (GJL) in relation to the menstrual cycle, which was divided into four phases based on basal body temperature and ovulation, assessed using an ovulation kit.

Methods: Participants were 14 female college students (21-22 years) with normal menstrual cycles (cis gender). Anterior drawer stress to a magnitude of 120 N was applied for all participants.

The Effects of Differences in the Morphologies of the Ulnar Collateral Ligament and Common Tendon of the Flexor-Pronator Muscles on Elbow Valgus Braking Function: A Simulation Study.

The anterior bundle (AB) and posterior bundle (PB) of the ulnar collateral ligament and the anterior common tendon (ACT) and posterior common tendon (PCT) of the flexor-pronator muscles have an independent form and an unclear form. The purpose of this study was to clarify the effect of differences in the morphologies of the AB, PB, ACT, and PCT on the elbow valgus braking function. This investigation examined three elbows.

Morphological Features of the Ulnar Collateral Ligament of the Elbow and Common Tendon of Flexor-Pronator Muscles.

Background: The anterior bundle (AB) of the ulnar collateral ligament is the most important structure for valgus stabilization of the elbow. However, anatomic relationships among the AB, posterior bundle (PB) of the ulnar collateral ligament, and common tendon (CT) of the flexor-pronator muscles have not been fully clarified.

Purpose: To classify the AB, PB, and CT and to clarify their morphological features.

Morphological features of the lateral plantar ligament of the transverse metatarsal arch.

The aim of this study was to elucidate the morphological characteristics of the lateral Lisfranc ligament in a large sample. This investigation examined 100 legs from 50 cadavers. Each of the lower limbs was dissected to identify the plantar aspect of the transverse metatarsal arch, and morphological characteristics of the lateral plantar ligament were assessed, including the length, width, and thickness of the fiber bundles.

Anatomic Characteristics of Tissues Attached to the Fifth Metatarsal Bone.

Background: Two types of stress, bending stress and traction stress, have been reported to be involved in the mechanism of Jones fracture. However, little is known about the risk factors for traction stress.

Purpose: To classify the attachment position of the peroneus brevis muscle (PB), peroneus tertius (PT), lateral band of the plantar aponeurosis (LB), and the long plantar ligament (LPL), focusing on the zone where a Jones fracture occurs (zone 2), and to compare the footprint area of each tissue type.

A new method for estimating three-dimensional movement of the patella using a surface mapping method and computed tomography.

Introduction: A previous study reported a method called the 2D-3D registration technique to examine three-dimensional movement of the patella. However, that method requires a biplane fluoroscopy system. In the present study, the aim was to establish a new method (CT-based surface mapping method) to estimate three-dimensional positions and angles of the patella with a motion capture system and CT.

Anatomical variations in the insertion of the peroneus longus tendon.

Background: This study aimed to inspect anatomical variations in the insertion of the peroneus longus tendon (PLT) using a large sample of cadavers.

Methods: In total, 104 legs from 52 Japanese cadavers were used. The PLT was identified behind the lateral malleolus and carefully followed up to its insertion in the foot.

The origin structure of each finger in the flexor digitorum superficialis muscle.

Purpose: The flexor digitorum superficialis muscle (FDS) is considered the most important of the forearm flexors for maintaining elbow valgus stability. However, the relationships between the origin structure of each finger of the FDS and the anterior oblique ligament (AOL) of the ulnar collateral ligament and the common tendon (CT) in the proximal part, and morphological features are unclear. The purpose of this study was to clarify the relationships between the origin structure of each finger of the FDS and the AOL and the CT, as well as to clarify the morphological features of the muscle belly of each finger of the FDS.