Takumi Okunuki

Objective evidence regarding the local effects of cupping on muscle and fascial stiffness remains limited. We investigated the acute effects of posterior lower leg cupping on ankle dorsiflexion range of motion (ROM), muscle and fascial stiffness assessed by shear-wave elastography (SWE), and lower-leg muscle activity during passive dorsiflexion. Sixteen healthy university students (10 men and 6 women; age: 20.7 ± 0.8 years; height: 173.4 ± 8.0 cm; body mass: 69.1 ± 9.8 kg) underwent cupping (CUP; moving cupping applied to the posterior lower leg for 1 min) and control (CON; 5 min supine rest) conditions in random order with a minimum 1-week washout period. The shear moduli of the deep fascia, superficial portion of the medial gastrocnemius (UMG) alongside its middle and deep portions, and deep intermuscular fascia were measured using SWE before and immediately after each condition. Ankle dorsiflexion ROM and lower-leg muscle activity during passive dorsiflexion were also assessed. Significant condition × time interactions were observed for ROM (F = 31.10, p < 0.001, η2p = 0.675), deep fascia (F = 10.38, p = 0.006, η2p = 0.409), and UMG (F = 11.73, p = 0.004, η2p = 0.439). Under CUP, ROM increased significantly (+5.65 ± 4.08°, p < 0.001, dz = 1.39), whereas shear moduli of deep fascia (-1.49 ± 1.06 kPa, p < 0.001, dz = -1.41) and UMG decreased significantly (-0.75 ± 0.51 kPa, p < 0.001, dz = -1.46). No significant changes occurred under CON for any of these variables. No significant changes were observed in the middle or deep portions of the medial gastrocnemius, deep intermuscular fascia, or muscle activity. A single bout of posterior lower leg cupping significantly reduced deep fascial and superficial medial gastrocnemius stiffness and increased ankle dorsiflexion ROM without altering muscle activity. These findings suggest that the mechanical effects of suction-based stimulation extend continuously from the skin through the deep fascia to the superficial muscle layer, and that the improvement in ROM is associated with changes in tissue mechanical properties rather than changes in neuromuscular activation.

Background/Objectives: Proximal hamstring injuries involving the biceps femoris–semitendinosus (BF–ST) conjoint tendon (CT) often exhibit delayed healing, yet the prognostic significance of CT involvement and intratendinous injury morphology has not been fully clarified. This study aimed to determine whether full-layer CT injury, particularly bilateral involvement in Zone C, prolongs return-to-play (RTP) in competitive rugby athletes. Methods: This prospective study evaluated 41 university rugby players with acute BF–ST complex injuries using clinical examination, ultrasonography, and MRI. Injuries were classified by Type (I: full-layer CT; II: BFLH-only; III: ST-only), Zone (A–E), and Grade (0–3). RTP was defined as unrestricted return to team training or match play. Group differences were analyzed using ANOVA or non-parametric tests with appropriate post hoc corrections. Results: Type I injuries required significantly longer RTP (11.4 ± 4.8 weeks) than Type II (5.3 ± 2.4 weeks) and Type III (4.0 ± 1.7 weeks), confirming the strong impact of CT involvement on prognosis. In Zone C, bilateral full-layer CT involvement was associated with an approximately twofold longer RTP duration compared with unilateral BFLH-side injuries, indicating that intratendinous tissue disruption influences recovery. These findings highlight the importance of early MRI-based assessment to identify clinically relevant tendon involvement patterns. Conclusions: Full-layer CT injuries, particularly bilateral intratendinous patterns in Zone C, markedly prolong RTP compared with isolated BFLH or ST injuries. An MRI-based classification incorporating injury type, zone, and extent of CT involvement provides clinically valuable prognostic information and may enhance RTP decision-making.

Introduction: Demi-pointe is a characteristic movement in female ballet dancers that requires sufficient foot and ankle joint range of motion (ROM) and muscle strength. This ROM may result from the combined motion of the foot and ankle joints. However, no studies have investigated the characteristics of forefoot varus/valgus ROM and the relationship between ROM and muscle cross-sectional area (CSA) in ballet dancers. Therefore, this study aimed to compare ballet dancers and non-dancers to clarify the characteristics of foot and ankle ROM and CSA of the intrinsic and extrinsic foot muscles and the relationship between ROM and CSA in ballet dancers. Methods: This study included 12 female ballet dancers (24 legs) and 11 non-dancers (22 legs). The ROM of the foot and ankle joints—including plantar flexion and forefoot varus/valgus—and CSA of the intrinsic foot muscle (abductor hallucis, abductor digiti minimi, flexor hallucis brevis, flexor digitorum brevis, and quadratus plantae) and extrinsic foot muscles (peroneus longus, flexor hallucis longus, flexor digitorum longus, and tibialis anterior) were evaluated and compared between the two groups. The relationship between ROM and CSA was also examined. Results: Compared with non-dancers, ballet dancers exhibited greater plantar flexion and forefoot valgus and reduced varus. The CSA of the intrinsic foot muscles and the peroneus longus muscle were significantly greater in ballet dancers. In ballet dancers, a significant negative correlation was observed between the ROM and CSA. Among the ROM variables examined, forefoot valgus showed a significant negative correlation with the CSA of multiple muscles. Conclusions: Ballet dancers demonstrated greater foot and ankle ROM in the sagittal and frontal planes, along with a larger intrinsic foot muscle CSA compared to non-dancers. Among these features, increased forefoot valgus and a negative correlation between forefoot valgus and CSA are particularly noteworthy as it has not been previously reported.

Background: Proximal hamstring injuries involving the biceps femoris–semitendinosus (BF–ST) conjoint tendon are clinically challenging, yet the prognostic impact of full-layer conjoint tendon (CT) injuries remains unclear. This study aimed to determine whether CT involvement prolongs the time to return to play (RTP) compared with isolated BFLH or ST injuries. Methods: A prospective cohort of 41 university rugby players with acute proximal BF–ST complex injuries was evaluated using standardized physical examination, ultrasonography, and MRI. Injuries were classified by Type (I: full-layer CT; II: BFLH-only; III: ST-only), Zone (A–E), and Grade (0–3). RTP was defined as full participation in team training or competition. RTP differences among Types and, within Type I, across Zones and Grades were analyzed using appropriate parametric or non-parametric tests. Results: Type I injuries required significantly longer RTP (11.4 ± 4.8 weeks) than Type II (5.3 ± 2.4 weeks) or Type III (4.0 ± 1.7 weeks). In Zone C, bilateral involvement of both BFLH and ST resulted in longer RTP than unilateral BFLH injury. Within Type I, Zone A (origin detachment) showed the longest RTP (20 weeks), exceeding Zones B and C. Higher Grades were also associated with prolonged recovery. Conclusions: Full-layer CT injuries represent a distinct clinical entity with markedly delayed RTP compared with isolated BFLH or ST injuries. Classification that distinguishes CT involvement provides useful prognostic information and may enhance RTP planning in athletes.

Introduction: A previous study confirmed the presence of adipose tissue along the posteromedial tibial border. This tissue may be the cause of medial shin pain, such as in medial tibial stress syndrome. However, the morphological and immunohistochemical characteristics of adipose tissue along the posteromedial tibial border remain unclear. In this study, we investigated the morphological and immunohistochemical characteristics of this tissue and compared them to those of the heel fat pad. Methods: Seven cadavers were fixed in 10% formalin solution, and specimens were sampled from the adipose tissue along the posteromedial tibial border and heel fat pad. Results: Scanning electron microscopy images showed a basket-like fibrous structure surrounding the adipocytes. This fibrous structure formed a three-dimensional network connecting adipocytes in both the posteromedial tibial border and the heel fat pad. The area and perimeter of the adipocytes were not significantly different between the adipose tissue along the posteromedial tibial border and the heel fat pads. Additionally, immunohistochemical staining confirmed that the fibres around the adipocytes were type I and III collagen fibres. These adipose tissues also reacted positively to substance P. Conclusion: The morphological and immunohistochemical characteristics of the adipose tissue along the posteromedial tibial border may be a structure adapted to carry mechanical stress. Additionally, the presence of substance P indicated that the adipose tissue along the posteromedial tibial border may be a source of pain, such as that experienced in medial tibial stress syndrome.