京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12919号 / 論医博第2094号 / 新制||医||1009(附属図書館) / 32129 / (主査)教授 戸口田 淳也, 教授 妻木 範行, 教授 安達 泰治 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DGAM

The identification of risk factors associated with overuse injuries, specifically Medial Tibial Stress Syndrome (MTSS) and Tibial Stress Fractures (TSF), may help professionals with management and prevention of these injuries. The purpose of this study was to identify risk factors associated with MTSS and TSF in female intercollegiate athletes. This study used a mulitifactorial, prospective design for 13-26 weeks. Thirty-nine Division I intercollegiate female student-athletes in volleyball, soccer, and track were examined. Anatomical, physiological (eating disorder and menstrual history), and training (duration and recovery time) characteristics were examined as possible risk factors. Only two injuries were reported during the study; therefore, analysis for risk factors was not possible. Descriptive statistics for the dependent variables were calculated, and comparisons across sport were performed. Differences in leg length values and dorsiflexion ROM were observed across sports. No conclusions could be drawn regarding possible risk factors for MTSS and TSF in this population.

Introduction: Foot over-pronation, attributable to Tibialis Posterior (TP) muscle weakness, is a possible cause of medial tibial stress syndrome (MTSS)3. Taping may provide a viable alternative for a dysfunctional TP and its associated navicular drop (ND). The most commonly used Augmented LowDye (ALD) technique has shown to prevent ND, but is time- and cost- intensive, leading us to explore an alternative technique. The purpose of this study was to assess the effectiveness of a new, anti-pronation (AP) taping technique, as compared to the ALD, to (a) reduce or prevent ND and (b) cause a lateral shift in the center of pressure (COP) measures. Methods: This is a 2 (tape techniques) by 3 (time: baseline, tape/pre-exercise, and tape/post-exercise) controlled laboratory study design. Twenty symptomatic (ND >/= 10 mm) college-age subjects were prepared with one of the 2 tape techniques and/or control and performed the ND test three times and walk across a pressure mat five times. Then the participants fatigued the tape by walking on a treadmill for 15 minutes at 3.0 mph at 0% grade and ND and pressure mat readings were recorded again. A within and within ANOVA allowed for the examination of between and within comparisons and a functional analysis (lateral shift as a function of time) on the mat-generated data were done p<.05. Results: Results revealed significant differences across times, and a times-by-tape technique interaction but differences between tape techniques were not significant. M and SD and indicate that while both taping techniques reduced ND, only the AP technique was significantly different (HSDTukey (3,76)=1.44, p<.01) for every comparison other than AP pre-exercise, the mean lateral shift for the treatment was not significantly different from the control across any part of the normalized stance phase, but was significantly lower than the control in the 30-90% interval in the AP pre-exercise. Discussion: The AP technique not only controlled ND but also resulted in an increase in lateral excursion of the COP line during that portion of the stance phase associated with the structures and functions of the TP. Both techniques can be appropriately used but that the AP can be used with more confidence in its effectiveness. The MatScan has allowed examination of forefoot pronation in the horizontal plane, not just the vertical plane, yielding a more holistic analysis of forefoot pronation. Being able to analyze data in a functional fashion (i.e., lateral shift as a function of time) could allow researchers greater insights to the complex relationships between biomechanical movement and appropriate interventions.

Introduction: The New Balance Core Low Cut Sock (New Balance Athletic Shoe, Inc. · Boston, MA United States) is one of many arch support socks out in the market. These socks have an elastic portion, called a Stability Fit Arch Support & Hold technology, which has been incorporated into the arch area of the sock. The company makes the following claim that the socks provide, "Gentle compression to support the arch, relieving arch-related pain and discomfort."1 If these socks do provide adequate arch support, then they would allow individuals the ability to have an inexpensive method of arch support that is easy to apply and use. The purpose of this study is to test the effectiveness of these socks in (a) navicular drop (b) static pressure insole pressure profiles and (c) dynamic (walking and running) pressure insole pressure profiles. Methods: Eighteen symptomatic, college age (age 18-26) subjects were used in this study (seven male, eleven female), with symptomatic being defined as a navicular drop greater than or equal to 10 mm. Measurements were collected for both the navicular drop, and F-Scan insole data, for both static and dynamic stance. For walking and running trials, heel strike and toe off were identified by the Tekscan System and COP excursion coordinates evaluated throughout the stance phase. The COP coordinates were exported then compared over the stance phase. A series of functional analyses was used to assess the between group differences. A paired t-test was used to assess the within group differences. Results: Results indicate that the arch support socks were not significantly different from the control (regular socks) along any part of the foot strike (95% confidence) in any of the conditions (standing, walking or running). Results from the paired t-test revealed no significant differences in navicular drop between sock types (p = .379). Discussion: This study found that the elastic band in the New Balance socks did not provide increased support to the medial arch of the foot compared to the control sock in either the navicular drop paired t-test or the functional analysis of the static and dynamic data. The authors could not find any other comparable study on these kinds of socks. Compared to other reports, using both orthotic inserts and tape, ND was reduced, unlike the results found in the present study. 2 Our data are inconsistent with the idea that increased elastic support to the midfoot by these socks provides significant arch support. The authors would suggest another form of arch support such as orthotics or taping to aid on arch support rather than these socks.

It is estimated that approximately 10-12% of the adult population suffers from osteoarthritis (OA), with long reaching burdens personally and socioeconomically. OA also causes mild discomfort to severe pain in those suffering from the disease. The incidence rate of OA for individuals with transtibial amputations is much than average in the tibiofemoral joint (TF). It is well understood that abnormal articular cartilage stress, whether that be magnitude or location, increases the risk of developing OA. Finite element (FE) simulations can predict stress in the TF joint, many studies throughout the years have validated the technology used for this purpose. This thesis is the first to successfully validate a procedure for creating subject-specific FE models for transtibial amputees to simulate the TF joint in gait, cycling and elliptical exercises. Maximum tibial cartilage pressure was extracted post-simulation and compared to historical data. The body weight normalized contact pressure on the tibial articular cartilage for the two amputee participants was larger in magnitude than the control participant in all but the medial compartment in cycling. Additionally, cycling exercise produced the smallest values of contact pressure with elliptical and gait producing similar max values but different areas of effect. The results from this thesis align with the body of work preceding it and further the goal of a FE model that predicts in-vivo articular cartilage stress in the TF joint. Future studies can further refine this methodology and create additional subject-specific models to allow for a statistical analysis of the observed differences to find if the results are significantly different. Refining the methodology could include investigating the full effect of the damping factor on contact pressure and exploring alternative methods of mesh generation.

Yes / If a prosthetic foot creates resistance to forwards shank rotation as it deforms during loading, it will exert a braking effect on centre of mass progression. The present study determines whether the centre of mass braking effect exerted by an amputee's habitual rigid ‘ankle’ foot was reduced when they switched to using an ‘Echelon’ hydraulic ankle–foot device. Nineteen lower limb amputees (eight trans-femoral, eleven trans-tibial) walked overground using their habitual dynamic-response foot with rigid ‘ankle’ or ‘Echelon’ hydraulic ankle–foot device. Analysis determined changes in how the centre of mass was transferred onto and above the prosthetic-foot, freely chosen walking speed, and spatio-temporal parameters of gait. When using the hydraulic device both groups had a smoother/more rapid progression of the centre of pressure beneath the prosthetic hindfoot (p ≤ 0.001), and a smaller reduction in centre of mass velocity during prosthetic-stance (p < 0.001). As a result freely chosen walking speed was higher in both groups when using the device (p ≤ 0.005). In both groups stance and swing times and cadence were unaffected by foot condition whereas step length tended (p < 0.07) to increase bilaterally when using the hydraulic device. Effect size differences between foot types were comparable across groups. Use of a hydraulic ankle–foot device reduced the foot's braking effect for both amputee groups. Findings suggest that attenuation of the braking effect from the foot in early stance may be more important to prosthetic-foot function than its ability to return energy in late stance.

yes / Background: Minimum toe clearance is a critical gait event because it coincides with peak forward velocity of the swing foot, and thus, there is an increased risk of tripping and falling. Trans-tibial amputees have increased risk of tripping compared to able-bodied individuals. Assessment of toe clearance during gait is thus clinically relevant. In able-bodied gait, minimum toe clearance increases with faster walking speeds, and it is widely reported that there is synchronicity between when peak swing-foot velocity and minimum toe clearance occur. There are no such studies involving lower-limb amputees. Objectives: To determine the effects of walking speed on minimum toe clearance and on the temporal relationship between clearance and peak swing-foot velocity in unilateral trans-tibial amputees. Study design: Cross-sectional. Methods: A total of 10 trans-tibial participants walked at slow, customary and fast speeds. Minimum toe clearance and the timings of minimum toe clearance and peak swing-foot velocity were determined and compared between intact and prosthetic sides. Results: Minimum toe clearance was reduced on the prosthetic side and, unlike on the intact side, did not increase with walking speed increase. Peak swing-foot velocity consistently occurred (~0.014 s) after point of minimum toe clearance on both limbs across all walking speeds, but there was no significant difference in the toe–ground clearance between the two events. Conclusion: The absence of speed related increases in minimum toe clearance on the prosthetic side suggests that speed related modulation of toe clearance for an intact limb typically occurs at the swing-limb ankle. The temporal consistency between peak foot velocity and minimum toe clearance on each limb suggests that swing-phase inter-segmental coordination is unaffected by trans-tibial amputation. Clinical relevance The lack of increase in minimum toe clearance on the prosthetic side at higher walking speeds may potentially increase risk of tripping. Findings indicate that determining the instant of peak swing-foot velocity will also consistently identify when/where minimum toe clearance occurs.

No description available.

Running popularity has led to a rise in chronic lower limb injuries resulting from cumulative loading. Many of these injuries are tibial stress fractures. Tibial accelerometers are commonly used to measure tibial stress and may even be predictive of injury at the distal limb. Lower body positive pressure (LBPP) treadmills have become increasingly popular amongst athletes and practitioners to prevent and treat lower limb injuries by reducing effective body weight (BW) through mechanical support. The purpose of this thesis is to investigate if BW unloading affects tibial acceleration (TA) and shock attenuation. Twelve trained distance runners (Sex: 6 males and 6 females; Age: 18-30 years) were recruited for this study. TA was measured through two Blue Trident, IMeasureU step units located at the distal tibiae. A STATSports Apex unit was also used to measure acceleration at the superior trunk and calculate shock attenuation for each limb. It was found that BW unloading had no discernable effect on mean peak TA and shock attenuation, bone stimulus, or contact time, regardless of running speed. However, a significant relationship was observed between running speed and both mean peak TA and bone stimulus where an increase in speed led to an increase in TA and bone stimulus. Furthermore, running speed did not affect shock attenuation or contact time. In conclusion, BW unloading did not alter gait kinematics in trained distance runners. / Master of Science / Running popularity has led to a rise in chronic lower limb injuries, particularly stress fractures at the shin or tibia bone, due to greater impact forces and "stiffer" landings. Tibial accelerometers are commonly used to measure these impact forces and may even be predictive of injury at the tibia bone near the ankle. The process of reducing these impact forces is called shock attenuation. Lower body positive pressure (LBPP) treadmills have become increasingly popular amongst athletes and practitioners to prevent and treat lower limb injuries by unloading body weight (BW) through mechanical support. The purpose of this thesis is to investigate if BW unloading affects tibial acceleration (TA) and shock attenuation. Twelve trained distance runners (Sex: 6 males and 6 females; Age: 18-30 years) were recruited for this study. TA was measured through two Blue Trident, IMeasureU step units located at the shin. A STATSports Apex unit was also used to measure impact at the upper trunk and calculate shock attenuation for each limb. It was found that BW unloading did not affect mean peak TA and shock attenuation, bone stimulus, or contact time, regardless of running speed. However, running speed significantly affected both mean peak TA and bone stimulus where an increase in speed led to an increase in TA and bone stimulus. Furthermore, running speed did not affect shock attenuation or contact time. In conclusion, BW unloading did not alter impact forces in trained distance runners. Caution is advised for individuals with injuries at the shin when using LBPP treadmills.

Objective: To evaluate the relative position of the femur and tibia in cranial cruciate ligament (CCL) intact stifles, CCL deficient stifles, and stifles following a novel extracapsular procedure (lateral extracapsular suture system or LESSa) under load at specific joint angles. Study Design: In vitro biomechanical study. Methods: Twenty pelvic limbs from 11 dogs were used to evaluate the relative position of the femur and tibia between 3 stifle conditions (CCL intact, CCL deficient, and LESSa treated) at a load of 30 % and stifle angles of 125", 135", and 145" using electromagnetic tracking sensors. Results: Cranial cruciate ligament deficient stifles had significantly greater (p <0.0001) cranial displacement and internal rotation of the tibia relative to the femur than CCL intact stifles or LESSa treated stifles at all stifle angles. Cranial displacement of the tibia relative to the femur for CCL intact and LESSa treated were not significantly different from one another at stifle angles of 125", but were significantly different at stifle angles of 135" (p = 0.0182) and 145" (p = 0.0012). There was no significant difference in internal rotation of the tibia relative to the femur between CCL intact and LESSa treated stifles at any of the stifle angles. Conclusion: LESSa effectively decreases cranial tibial displacement and eliminates internal rotation of the tibia relative / Master of Science