Objective To compare the effect of immediately wearing different running shoes and foot-strike patterns on the in vivo Achilles tendon(AT)length and loading of habitual rearfoot striking(RFS)runners.Methods Eleven male running enthusiasts were recruited(age:33.7±8.7 years old,running experience:5.3±2.3 years).They were randomly assigned to wear cushioned running shoes or minimalist shoes,and run at 10 km/h on a Bertec 3-D force platform with forefoot striking(FFS)and RFS,respectively.The ultrasound imaging probe was fixed at the junction of the AT and the me-dial head of the gastrocnemius muscle with an elastic bandage,synchronized with the Vicon high-speed infrared motion capture system,which collected and calculated real-time length changes and loading characteristics of the AT in vivo.A 2×2 two-way ANOVA was used to determine the effect of different running shoes(cushioned running shoes vs.minimalist shoes)and foot strike patterns(FFS vs.RFS)on the in vivo AT loading characteristics during running,and the significance level α was set at 0.05.Results There was a significant interaction between footwear type and footstrike patterns on the foot strike angle.Within the same shoe condition(cushioned or minimalist),foot strike angle(FSA)was significantly greater during RFS than during FFS(P<0.05).Moreover,during RFS,FSA was significantly greater in cushioned shoes than in minimalist shoes(P<0.05).In addition,under acute manipulations of footwear and strike pattern,the instantaneous AT loading rate also exhibited a signifi-cant footwear and foot strike patterns interaction(P<0.05).The instantaneous AT loading rate was sig-nificantly greater when immediately wearing minimalist shoes with RFS than when wearing cushioned running shoes with RFS,as well as significantly greater when immediately wearing cushioned running shoes with FFS than when running with RFS(P<0.05).In addition,there was no interaction effect for the other parameters,except the significant group or time main effects(P<0.05).The peak AT force,average AT loading rate,AT impulse,peak AT stress,peak AT length change,and AT work during FFS were significantly greater than those during RFS(P<0.05).What's more,the peak AT force when immediately wearing minimalist shoes was significantly greater than that when wearing cushioned run-ning shoes(P<0.05).Conclusion It is suggested that immediately wearing minimalist shoes and/or transi-tioning to FFS could provide higher tendon loading intensity,which might improve the morphology and mechanical properties of the AT.However,the increased AT loading rate also indicated that if RFS was maintained while running in minimalist shoes,the reduced cushioning could have led to a greater risk of injury without an appropriate adaptation process.

Objective To compare the effect of immediately wearing different running shoes and foot-strike patterns on the in vivo Achilles tendon(AT)length and loading of habitual rearfoot striking(RFS)runners.Methods Eleven male running enthusiasts were recruited(age:33.7±8.7 years old,running experience:5.3±2.3 years).They were randomly assigned to wear cushioned running shoes or minimalist shoes,and run at 10 km/h on a Bertec 3-D force platform with forefoot striking(FFS)and RFS,respectively.The ultrasound imaging probe was fixed at the junction of the AT and the me-dial head of the gastrocnemius muscle with an elastic bandage,synchronized with the Vicon high-speed infrared motion capture system,which collected and calculated real-time length changes and loading characteristics of the AT in vivo.A 2×2 two-way ANOVA was used to determine the effect of different running shoes(cushioned running shoes vs.minimalist shoes)and foot strike patterns(FFS vs.RFS)on the in vivo AT loading characteristics during running,and the significance level α was set at 0.05.Results There was a significant interaction between footwear type and footstrike patterns on the foot strike angle.Within the same shoe condition(cushioned or minimalist),foot strike angle(FSA)was significantly greater during RFS than during FFS(P<0.05).Moreover,during RFS,FSA was significantly greater in cushioned shoes than in minimalist shoes(P<0.05).In addition,under acute manipulations of footwear and strike pattern,the instantaneous AT loading rate also exhibited a signifi-cant footwear and foot strike patterns interaction(P<0.05).The instantaneous AT loading rate was sig-nificantly greater when immediately wearing minimalist shoes with RFS than when wearing cushioned running shoes with RFS,as well as significantly greater when immediately wearing cushioned running shoes with FFS than when running with RFS(P<0.05).In addition,there was no interaction effect for the other parameters,except the significant group or time main effects(P<0.05).The peak AT force,average AT loading rate,AT impulse,peak AT stress,peak AT length change,and AT work during FFS were significantly greater than those during RFS(P<0.05).What's more,the peak AT force when immediately wearing minimalist shoes was significantly greater than that when wearing cushioned run-ning shoes(P<0.05).Conclusion It is suggested that immediately wearing minimalist shoes and/or transi-tioning to FFS could provide higher tendon loading intensity,which might improve the morphology and mechanical properties of the AT.However,the increased AT loading rate also indicated that if RFS was maintained while running in minimalist shoes,the reduced cushioning could have led to a greater risk of injury without an appropriate adaptation process.

This study investigates the pharmacokinetics and metabolic characteristics of three marine-derived piericidins as potential drug leads for kidney disease: piericidin A (PA) and its two glycosides (GPAs), glucopiericidin A (GPA) and 13-hydroxyglucopiericidin A (13-OH-GPA). The research aims to facilitate lead selection and optimization for developing a viable preclinical candidate. Rapid absorption of PA and GPAs in mice was observed, characterized by short half-lives and low bioavailability. Glycosides and hydroxyl groups significantly enhanced the absorption rate (13-OH-GPA > GPA > PA). PA and GPAs exhibited metabolic instability in liver microsomes due to Cytochrome P450 enzymes (CYPs) and uridine diphosphoglucuronosyl transferases (UGTs). Glucuronidation emerged as the primary metabolic pathway, with UGT1A7, UGT1A8, UGT1A9, and UGT1A10 demonstrating high elimination rates (30%-70%) for PA and GPAs. This rapid glucuronidation may contribute to the low bioavailability of GPAs. Despite its low bioavailability (2.69%), 13-OH-GPA showed higher kidney distribution (19.8%) compared to PA (10.0%) and GPA (7.3%), suggesting enhanced biological efficacy in kidney diseases. Modifying the C-13 hydroxyl group appears to be a promising approach to improve bioavailability. In conclusion, this study provides valuable metabolic insights for the development and optimization of marine-derived piericidins as potential drug leads for kidney disease.
Animals ; Male ; Mice ; Aquatic Organisms/chemistry* ; Biological Availability ; Cytochrome P-450 Enzyme System/metabolism* ; Glucuronosyltransferase/metabolism* ; Microsomes, Liver/metabolism* ; Molecular Structure ; Biological Products/pharmacokinetics* ; Pyridines/pharmacokinetics*

The triceps surae muscle-tendon unit(MTU)is the key for effective force generation,transmission,and energy storage and release in human movement,with great influences on sports efficiency,but its injury rate remains high.This review summarizes MTU function and its biomechanical adaptations during running,aiming to deepen the understanding of MTU's role in movement and explore how external factors influence its biomechanical properties,offering scientific insights for improving running performance and preventing injuries.During running,under forefoot striking and wearing shoes with greater stiffness,such as shoes with carbon plate,the energy contraction or return could be achieved through a more economical MTU behavior,namely reducing energy consumption by more economically muscle contraction and more energy storage of elastic elements,and the muscle contraction was exerted at a length closer to the optimal muscle fascicle length and reduced energy consumption caused by muscle contraction.However,adopting forefoot striking,barefoot running,or wearing minimalist shoes during running could increase the mechanical loads on the MTU.After gait retraining,the MTU could contract or return energy more efficiently during running,while the impact of other training methods on MTU was relatively poor,and the research in this area is still not sufficient.Therefore,future research should focus on optimizing the biomechanical properties of the MTU,MTU interaction and balanced development through changes in movement patterns,equipment,and training methods to enhance performance and reduce injuries.

The triceps surae muscle-tendon unit(MTU)is the key for effective force generation,transmission,and energy storage and release in human movement,with great influences on sports efficiency,but its injury rate remains high.This review summarizes MTU function and its biomechanical adaptations during running,aiming to deepen the understanding of MTU's role in movement and explore how external factors influence its biomechanical properties,offering scientific insights for improving running performance and preventing injuries.During running,under forefoot striking and wearing shoes with greater stiffness,such as shoes with carbon plate,the energy contraction or return could be achieved through a more economical MTU behavior,namely reducing energy consumption by more economically muscle contraction and more energy storage of elastic elements,and the muscle contraction was exerted at a length closer to the optimal muscle fascicle length and reduced energy consumption caused by muscle contraction.However,adopting forefoot striking,barefoot running,or wearing minimalist shoes during running could increase the mechanical loads on the MTU.After gait retraining,the MTU could contract or return energy more efficiently during running,while the impact of other training methods on MTU was relatively poor,and the research in this area is still not sufficient.Therefore,future research should focus on optimizing the biomechanical properties of the MTU,MTU interaction and balanced development through changes in movement patterns,equipment,and training methods to enhance performance and reduce injuries.

Objective To investigate the effects of different foot strike patterns during running on Achilles tendon(AT)morphology and mechanical loading.Methods Fourteen habitual rearfoot strike runners and 14 habitual forefoot strike runners were recruited.Morphological characteristics(tendon length,cross-sectional area,and thickness)of the AT were collected using ultrasound imaging.The AT loading characteristics(plantar flexion moment,tendon force,load rate,impulse,and stress)of subjects wearing cushioned running shoes while running at a speed of 10 km/h were collected and calculated using a three-dimensional force measurement treadmill.Results Compared to habitual rearfoot strike runners,habitual forefoot strike runners showed a significant increase in peak plantar flexion moment of ankle joint,AT peak force,average loading rate,and peak loading rate(P<0.05).However,the differences in AT length,cross-sectional area,and thickness between the two groups were not statistically significant(P>0.05).Conclusions Long-term forefoot strike patterns can adaptively enhance the mechanical loading characteristics of the AT during repetitive stretch-shortening cycles.

Objective: To examine the safety and effectiveness of a new stent graft system for endovascular repair of abdominal aortic aneurysm(AAA). Methods: This is a prospective,multi-center,single-arm clinical trial. The patients with AAA treated with a new stent graft system were enrolled at 21 centers from September 2018 to September 2019 in China. Follow-up was performed before discharge, and at 30, 180, 360 days after operation, respectively. The primary safety endpoint was the incidence of major adverse events(MAE) within 30 days. The primary efficacy endpoint was the success rate of AAA treatment at 360 days. Secondary safety endpoints were the incidence of perioperative access complications and acute lower limb ischemia,all-cause mortality, AAA related mortality and incidence of serious adverse events (SAE) at 180 and 360 days. Secondary efficacy endpoints were the incidence of type Ⅰ or Ⅲ endoleak,stent displacement,and conversion to open surgery or re-intervention at 180 and 360 days. Results: One hundred and fifty-six patients were enrolled,including 137 males and 19 females. The age was (68.9±6.9) years (range:48.2 to 84.6 years).Maximum aneurysm diameter was (50.8±11.2) mm (range:25.0 to 85.0 mm),diameter of proximal landing zone was (21.2±2.5) mm (range:17.0 to 29.5 mm),and length of proximal landing zone was (31.4±13.0) mm (range:11.0 to 75.0 mm).The incidence of MAE was 1.3% (2/156) at 30 days,both were all-cause death cases. The success rate of AAA treatment was 88.5% (138/156) at 360 days. No perioperative access complication and acute lower limb ischemia occurred. All-cause mortality was 2.0% (3/154) at 180 days and 2.6% (4/153) at 360 days,and there was no AAA related death. The incidence of SAE was 23.0%(35/152) at 180 days and 30.5%(46/151) at 360 days, and no device-related SAE occurred. The incidence of type Ⅰor Ⅲ endoleak was 3.4% (5/147) at 180 days and 3.5% (5/144) at 360 days. Conclusion: The new stent graft system is easy to operate,and early-term safety and effectiveness results are expected.
Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Prospective Studies ; China ; Ischemia ; Aortic Aneurysm, Abdominal/surgery*

Objective To explore the correlation between foot morphology and toe/metatarsophalangeal joint muscle strength. Methods Twenty-six male recreational runners were recruited. Foot length, truncated foot length, foot width, navicular height, dorsum height at 50% of the foot length, metatarsophalangeal joint strength, tensile force of the first and remaining four toes were measured by using digital caliper, metatarsophalangeal joint strength tester and dynameter, respectively. Partial correlations were used to analyze the correlation between foot morphology and foot muscle strength. ResultsWith adjusted age and body mass index (BMI), the foot width in standing position and truncated foot length in sitting and standing position were positively correlated to tensile force of the first toe; the foot length, foot width and truncated foot length were positively correlated to tensile force of the remaining four toes in both positions, and the arch height index in sitting position was negatively associated with tensile force of the remaining four toes; the foot width was positively correlated to metatarsophalangeal joint strength in both positions. Conclusions The longer foot length, foot width, truncated foot length, and the lower arch height in normal range might be related to the larger foot muscle strength. The consideration of the differences in foot morphological characteristics in different positions during the measurement of foot morphology can provide references for predicting foot muscle strength and preventing foot injury.

Objective To investigate the mechanical properties of Achilles tendon (AT) during running under different shoe conditions (minimalist vs conventional shoes). MethodsSixteen healthy male runners with habitual rearfoot strike patterns were recruited to complete the running trials at the speed of 3.16~3.50 m/s under two shoe conditions. The cross-sectional area of the AT was obtained by ultrasound imaging. Sagittal plane ankle kinematics and ground reaction forces were recorded by motion capture system and three-dimensional force platform simultaneously. Mechanical properties of the ankle and AT were calculated. Paired t test was used to compare the effects of two shoe conditions on various parameters (ankle angle, strike angle, AT force, stress, strain, etc). ResultsCompared with conventional shoes, foot inclination angle was significantly reduced by 39.9% with minimalist shoes. Obvious increase in ankle moment, peak AT force, peak AT loading rate, average loading rate, and obvious decrease in time to peak AT force were observed with minimalist shoes. Peak AT stress, peak AT strain and corresponding stress rate, peak strain rate also increased significantly with minimalist shoes. ConclusionsGreater AT loading was observed when runners with habitual rearfoot strike pattern in conventional shoes begin to wear minimalist shoes. Therefore, a gradual transition to minimalist shoes was recommended for them so as to improve the ability to load adaptively.

The technical deficiencies in traditional medical imagining methods limit the study of
Ankle ; Ankle Joint ; Biomechanical Phenomena ; Range of Motion, Articular ; Technology