Acute effect of engineered thermoplastic polyurethane elastomer knockoff running footwear on foot loading and comfort during heel-to-toe running

BackgroundBetter midsole materials and comfort have been incorporated into more expensive shoes and are popular with runners. Consequently, knockoff running shoes are currently widely distributed in the Chinese market and and cost only 30%–50% of the total price of genuine branded products.Research questionUncertainty exists concerning the beneficial effects of advanced shoe material application in decreasing foot loading or impact force during running. Additionally, using comfort as a criterion to identify genuine branded running shoes may exclude brand factor.MethodsFifteen healthy male volunteers were asked to perform two different tests, including running and a comfort evaluation. Each participant was asked to identify which footwear was the Adidas brand shoe based on their perception of comfort.ResultsTime to the first peak of the vertical ground reaction force occurred significantly later when subjects wore the genuine branded shoe compared to knockoff shoe 1 (p = 0.003) and knockoff shoe 2 (p = 0.015) footwea. The genuine branded shoe (p = 0.005) and knockoff shoe 1 (p = 0.029) were significantly more comfortable compared to the knockoff shoe 2. Only four subjects selected the genuine branded shoe, whereas six subjects selected both the genuine branded shoe and knockoff shoe 1.SignificanceKnockoff running footwear significantly increases impact loading compared to the genuine branded product, thereby posing greater risk of running injury.     

扁平足与正常足举重运动员足底压力分布对照研究

目的:调查举重运动员扁平足发病情况,分析对比扁平足和正常足举重运动员足底压力分布特点。方法:38名举重运动员,利用三线印迹法分为扁平足组和正常足组。采用Tekscan的HRMat System足底压力测试仪分别检测并分析两组对象中立位站立时的足底压力分布。结果:(1)38名举重运动员中扁平足14人,正常足24人。(2)扁平足组报告足部疼痛症状的比例为57.1%,正常足组为25%,二者间无显著差异(P>0.05);扁平足组膝关节疼痛者所占比例为64.7%,正常足组为41.7%,二者间无显著差异(P>0.05)。(3)扁平足组中足及第一跖骨力度百分比显著高于正常足组(P<0.05),而内、外侧足跟处力度百分比均显著高于正常足组(P<0.05)。(4)扁平足组中足接触面积以及接触面积百分比均显著高于正常足组(P<0.05),而扁平足组足跟内侧以及第三跖骨处接触面积百分比显著低于正常足组(P<0.05)。(5)扁平足组第一跖骨处接触压力显著高于正常足组(P<0.05),而其足跟外侧接触压力则显著低于正常足组(P<0.05)。(6)扁平足组足跟内侧峰值压力显著低于正常足组(P<0.05)。结论:本研究中扁平足组报告足踝部及膝关节疼痛症状的比例均高于正常足;扁平足举重运动员足底压力分布特点与正常足举重运动员不同,站立、负重时足底受力模式向脚掌中部及前部内侧转移,中足接触面积及力度百分比增大、第一跖骨压力升高。     

Influence of shoe midsole hardness on plantar pressure distribution in four basketball-related movements

This study examined how shoe midsole hardness influenced plantar pressure in basketball-related movements. Twenty male university basketball players wore customized shoes with hard and soft midsoles (60 and 50 Shore C) to perform four movements: running, maximal forward sprinting, maximal 45° cutting and lay-up. Plantar loading was recorded using an in-shoe pressure measuring system, with peak pressure (PP) and pressure time integral (PTI) extracted from 10 plantar regions. Compared with hard shoes, subjects exhibited lower PP in one or more plantar regions when wearing the soft shoes across all tested movements (Ps < 0.05). Lower PTI was also observed in the hallux for 45° cutting, and the toes and forefoot regions during the first step of lay-up in the soft shoe condition (Ps < 0.05). In conclusion, using a softer midsole in the forefoot region may be a plausible remedy to reduce the high plantar loading experienced by basketball players.     

Adding an arch support to a heel lift improves stability and comfort during gait

Heel lifts have been widely used as a conservative treatment for some musculoskeletal problems and complaints. However, the heel rise caused by heel lifts may also affect the plantar pressure distribution and stability during walking. This study aimed to test whether adding an arch support to a heel lift would improve its stability and comfort through comparing the center of pressure (COP) during walking and subjective ratings between heel lifts with and without an arch support. Fifteen healthy male participants were asked to walk along an 8 m walkway while wearing high-cut footwear with the control heel lifts and the heel lifts with an arch support. A Footscan pressure plate was used to measure the COP during walking. Subjective ratings including medial-lateral control, dynamic foot/shoe fitting and overall comfort were assessed for each participant. The results showed that compared to the control condition, the COP trajectory was medially shifted during stance phase of gait in the arch support condition. The maximum displacements and velocity of medial-lateral COP in the forefoot contact phase were smaller in the arch support condition than in the control condition. Adding an arch support to a heel lift also significantly improved the subjective ratings in terms of the medial-lateral control, dynamic foot/shoe fitting and overall comfort. The findings of this study suggest that adding an arch support to a heel lift could improve its stability and comfort during walking.     

有鞋带跑鞋和松紧鞋舌跑鞋跑步主观舒适度、足底压力和后足运动参数比较

目的:比较穿着鞋带跑鞋和采用松紧鞋舌跑鞋在主观舒适度、足底压力分布和后足运动参数方面的区别。方法:15名有经验的跑步者自愿参与本研究。采用一份可靠的问卷进行主观舒适度调查;采用Novel pedar足底压力测试系统记录受试者穿着两种跑鞋跑步时的足底压力分布;采用二维高速摄像系统和Ariel动作解析系统记录、分析受试者穿着两种跑鞋跑步时后足的运动图像及足跟相对小腿的内、外翻参数。结果:与穿着有鞋带跑鞋比较,受试者在穿着松紧鞋舌跑鞋跑步时的主观舒适度较差,第4和第5跖趾关节分区足底压强明显增加,后足外翻角度较大。结论:松紧鞋舌式设计并不适用于跑鞋。有鞋带跑鞋合脚性更好,可以帮助跑步者固定鞋内的脚。     

运动性疲劳对健康男大学生足底压力分布的影响

目的:分析运动性疲劳对健康男大学生足底压力分布的影响,为科学指导锻炼提供依据。方法:10名普通男大学生沿400米跑道慢跑至中度疲劳,应用0.5米footscan誖USB平板测试系统对受试者运动性疲劳产生前后足底压力分布情况进行测试。结果:与疲劳前相比,运动疲劳后,(1)受试者足跟着地阶段明显变短,足支撑阶段明显变长;(2)左足T2-T5、M2、M4、M5和右足T1、T2-T5、M2、M3、M5、HM、HL各区域与地面的压强峰值显著降低;左足T2-T5区域、右足T1和T2-T5区域与地面压强峰值出现时间显著缩短,而其它部位压强峰值出现时间有延迟趋势;(3)左足T2-T5区域与地面接触时间显著缩短,M2区域显著延长;右足M1、M2、M3区域显著延长;(4)左足T2-T5区域与地面的接触面积显著减小,T1、M3、M5区域显著增大,而其它部位均有增大的趋势;右足除M3显著减小外,其它区域均表现出下降的趋势;(5)左足T2-T5、M5区域和右足M2、M3区域所受压强在时间上的积累(Pt)显著减小;(6)足平衡总体上呈现内外翻程度增大的变化趋势,但10名受试者中有3例疲劳前后的变化不明显。结论:运动性疲劳导致下肢肌肉力量减弱等生理机能下降,从而引起步态分期、足底压力分布参数、足平衡等发生相应变化。     

Effects of rocker radii with two longitudinal bending stiffnesses on plantar pressure distribution in the forefoot

IntroductionOutsole parameters of the shoe can be adapted to offload regions of pain or region of high pressures. Previous studies already showed reduced plantar pressures in the forefoot due to a proximally placed apex position and higher longitudinal bending stiffness (LBS). The aim of this study was to determine the effect of changes in rocker radii and high LBS on the plantar pressure profile during gait.Method10 participants walked in seven shoe conditions of which one control shoe and six rocker shoes with small, medium and large rocker radii and low and high longitudinal bending stiffness. Pedar in-shoe plantar pressure measuring system was used to quantify plantar pressures while walking on a treadmill at self-selected walking speed. Peak plantar pressure, maximum mean pressure and force-time integral were analyzed with Generalized Estimated Equation (GEE) and Tukey post hoc correction (α = .05).ResultsSignificantly lower plantar pressures were found in the first toe, toes 2–5, distal and proximal forefoot in all rocker shoe conditions as compared to the control shoe. Plantar pressures in the first toe and toes 2–5 were significantly lower in the small radius compared to medium and large radii. For the distal forefoot both small and medium radii significantly reduced plantar pressure compared to large radii. Low LBS reduced plantar pressure at the first toe significantly compared to high LBS independent of the rocker radius. Plantar pressures in the distal forefoot and toes 2–5 were lower in high LBS compared to low LBS.ConclusionManipulation of the rocker radius and LBS can effectively reduce peak plantar pressures in the forefoot region during gait. In line with previous studies, we showed that depending on the exact target location for offloading, different combinations of rocker radius and LBS need to be adopted to maximize treatment effects.     

航海人员24小时动态血压与偶测血压的关系

目的　观测分析航海人员中高血压与正常血压者的 2 4h动态血压 (2 4h ABP)及偶测血压 (CBP) ,以探讨 CBP与动态血压监测 (ABPM)之间的相关性。方法　用标准水银柱式血压计测坐位左上臂血压 3次 ,取平均值作为 CBP的收缩压 (SBP)、舒张压 (DBP)和平均动脉压 (MAP)。用 ABPM获得2 4h动态血压的 2 4h SBP、2 4h DBP和 2 4h MAP,以及日间平均动态血压 (d ABP)的 d SBP、d DBP和d MAP,与夜间平均动态血压 (n ABP)的 n SBP、n DBP和 n MAP。结果　高血压组 CBP的平均 SBP、DBP、MAP均高于 d ABP和 2 4h ABP(P均 <0 .0 1) ;CBP与 d ABP间的 SBP、DBP、MAP均值的差值分别为13.2 ,10 .0和 11.6 m m Hg,并均明显高于血压正常组的两者差值 (P<0 .0 1)。 CBP法与血压负荷值法[d SBP或 d DBP>12 %或 (和 ) n SBP或 n DBP>15 % ]诊断高血压的一致性为 95 % ,而后者诊断的特异性为 99% ,敏感性为 84% ,白大衣性高血压 (WCH)发生率为 16 % ;CBP法与 d ABP法 (≥ 135 / 85 mm Hg)诊断高血压的一致性为 76 % ,而后者诊断的特异性为 84% ,敏感性为 5 4% ,WCH发生率为 45 .6 %。结论　 ABPM的负荷值法诊断高血压与 CBP的一致性及其诊断的敏感性与特异性均高于 d ABP法 ,提示负荷值法可能在临床诊断高血压等方面更有参考价值     

中国青年踝关节跖屈、背屈肌群力量的研究

目的 :(1 )通过测试健康青年踝关节背屈、跖屈肌群的力量 ,为运动训练、损伤和康复提供实验依据 ;(2 )探讨健康青年踝关节跖屈、背屈肌群工作的生物力学规律。方法 :利用CYBEX -60 0 0型测力系统对 70例健康青年 (男 35人 ,女 35人)踝关节背屈、跖屈肌群进行等长和等速测试。结果发现 :在等长测试中 ,男、女踝关节背屈肌群峰力矩均随测试角度的增加而增加 ,跖屈峰力矩随测试角的增加而减小。在等速向心测试中 ,男、女踝关节背屈、跖屈肌群峰力矩随测试角速度的增加而减小。两种测试均表明 ,跖屈肌群峰力矩大于背屈肌群峰力矩 (P <0 0 5)。男性与女性相比 ,绝对力矩较大(P <0 0 5) ;但去除体重因素后 ,男、女相对力矩间差距缩小。结果表明 ,用相对峰力矩比较男、女肌力的差别更为合理。通过对踝关节背屈 /跖屈肌群峰力矩比值的研究 ,发现我国健康青年普遍踝关节背屈肌群力量比较薄弱 ,推测这可能是导致踝关节易扭伤的原因之一     

Effect of a carbon reinforcement for maximizing shoe outsole bending stiffness on plantar pressure and walking comfort in people with diabetes at high risk of foot ulceration

BackgroundDifferent shoe design features can reduce peak plantar pressure to help prevent foot ulcers in people with diabetes. A carbon reinforcement of the shoe outsole to maximize bending stiffness is commonly applied in footwear practice, but its effect has not been studied to date.Research questionWhat is the effect of a carbon shoe-outsole reinforcement on peak plantar pressure and walking comfort in people with diabetes at high risk of foot ulceration?MethodsIn 24 high-risk people with diabetes, in-shoe regional peak pressures were measured during walking at a comfortable speed in two different shoe conditions: an extra-depth diabetes-specific shoe with a non-reinforced outsole and the same type of shoe with a 3-mm-thick full-length carbon reinforcement of the outsole. The same custom-made insole was worn in both shoe conditions. Walking comfort was assessed using a Visual Analogue Scale (0–10, 10 being highest possible comfort).ResultsSignificantly lower metatarsal head peak pressures (by a median 10–22 kPa) were found with the reinforced shoe compared to the non-reinforced shoe (p < .001). In >83% of cases with the reinforced shoe and >71% with the non-reinforced shoe metatarsal head peak pressures were <200 kPa. At the hindfoot, peak pressures were significantly higher (by a median 24 kPa) with the reinforced shoe (p = .001). No significant shoe effects were found for the toes. No significant shoe effects were found for walking comfort: median 6.1 for the reinforced shoe versus 5.6 for the non-reinforced shoe.SignificanceAdding a full-length carbon reinforcement to the outsole of a diabetes-specific shoe significantly reduces peak pressures at the metatarsal heads, where ulcers often occur, in high-risk people with diabetes, and this does not occur at the expense of patient-perceived walking comfort.     

In-shoe plantar pressure measurements for the evaluation and adaptation of foot orthoses in patients with rheumatoid arthritis: A proof of concept study

ObjectivesImproving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility.MethodsForty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure–time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.ResultsAdapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure–time integral at forefoot ROIs compared to no-FOs (p = 0.01). FO adaptation led to an additional mean 3% reduction in pressure–time integral (p = 0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed.ConclusionsUsing in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.     

Gait asymmetry in patients with limb length discrepancy

Foot loading patterns and neuromuscular function of both limbs during walking were investigated on 25 patients with limb length discrepancy. Plantar pressures and 2-D ground reaction forces were recorded simultaneously with electromyographic activities at two different walking speeds. Bilateral comparison indicated that moderate limb length discrepancies resulted in asymmetrical gait patterns. The duration of the stance phase was reduced in the short limb in both walking speeds. The vertical ground reaction force (F) in the push-off phase was greater in the long limb both at normal (1.33 (SO, 0.05 BW) vs. 1.29 (SD, 0.09 BW)) (P=0.0027) and fast walking speed (1.55 (SD, 0.11) vs. 1.48 (SD, 0.15 BW)) (P=0.001). Peak plantar pressures were higher under the big toe in the long leg and the heel-off occurred faster. The push-off phase was initiated earlier in the short leg. The maximum isometric torque of the long limb was considerably greater (673 Nm vs. 239 Nm) (P=0.026). The results imply that the loading of the long limb is greater and the foot loading patterns shifted more to the forefoot in the long, limb to compensate walking disturbances caused by limb length discrepancies.     

阿托伐他汀对高血压病患者脉压及血压昼夜节律的影响

目的：探讨他汀类调脂药阿托伐他汀对高血压患者脉压及血压昼夜节律的影响。方法：选取40例高血压患者（服用降压药后血压控制均达标）,监测其服用阿托伐他汀8周前后的24 h动态血压,比较服药前后脉压和血压昼夜节律的变化。结果：治疗后脉压减小,与治疗前比较差异有统计学意义（P〈0.05）;治疗后杓形节律增多,非杓形节律减少,与治疗前比较有统计学意义（P〈0.01）。结论：阿托伐他汀可以降低血压控制达标的高血压患者的脉压,一定程度上恢复其血压昼夜节律,从而更有效的控制血压。     

Effects of a novel inclined-adaptive footwear on change-of-direction performance in male athletes

BackgroundAlthough enhancing change of direction (COD) performance is a crucial factor for improving athletic performance in many sports, few studies have explored its effective methods.Research questionThis study aimed to investigate the effects of inclined-adaptive footwear (IAF) on force-time characteristics during a COD task.MethodsThirteen male team sport athletes were randomly assigned to wear IAF or footwear without adaptive technology to perform a COD60° task at their best effort. A three-dimensional force plate was used to obtain the force-time curve and related parameters at the turning step (plant foot).ResultsIAF led to a significantly higher resultant ground reaction force (GRF), horizontal GRF, vertical GRF, and horizontal/vertical ratio during the braking phase, followed by a significantly shorter contact time and higher resultant horizontal GRF and vertical GRF during the propulsive phase.SignificanceThis indicated that a greater GRF output, redistributed GRF, and shorter contact time occurred with the IAF. Therefore, IAF has the potential to enhance COD performance for sports involving multi-directional footwork and contribute to the development of new functional footwear.     

胫骨旋转对髌股关节应力分布的影响

为探明胫骨旋转畸形对髌股关节应力分布的影响,本实验选取7个新鲜离体膝关节,在屈膝30°、60°、90°状态下,分别用压敏片测量胫骨中立位、内旋10°、20°、30°和外旋10°、20°、30°时的内、外侧髌股关节接触压力与峰值。结果显示外旋过程中,外侧髌股关节的接触压均值和接触压峰值呈非线性递增趋势,内侧呈非线性递减趋势;内旋过程中,外侧髌股关节的接触压均值和峰值逐渐减小,内侧则增加显著。上述变化在内旋20°到外旋20°的范围内较有规律。提示胫骨旋转畸形使髌股关节应力分布严重失衡,可能是引起髌股关节退变的重要因素。     

Between-day reliability of repeated plantar pressure distribution measurements in a normal population

The objective of this study was to determine the reliability of repeated plantar pressure distribution measurements during normal gait across multiple testing sessions. Testing sessions were conducted on 5 separate days at approximately the same time of day. Nine subjects (five males, four females, age 26 ± 8.4 years) who were free of any musculoskeletal injury were recruited. A capacitive pressure distribution platform (EMED AT, Novel GmbH, Munich, Germany), sampling at 50 Hz was used to collect plantar pressure patterns during barefoot walking at a self-selected speed. Four parameters were investigated: peak pressure, maximum force, impulse, and contact time, and these were investigated in 10 areas of the foot after using the PRC mask method of subdividing the foot into ten anatomical areas of interest. Individual means of all the five repeated trials for each foot were calculated, and these values were used to calculate intraclass correlation coefficients (ICC) and coefficients of variation (CoV) for all parameters. The results of this investigation show a generally good level of reliability, the quality of which is dependent on the region of the foot and the parameter investigated. Areas with typically high loading characteristics, such as the central forefoot showed a higher level of reliability in the ICC's (>0.9) than less loaded areas such as the medial midfoot (<0.8). The conclusion of this study is that plantar pressure distribution measurements can be used in comparative evaluations since the measures of repeatability are satisfactory for the parameters and foot regions usually used in the investigation of clinical populations such as neuropathic diabetics.     

Foot pressure and center of pressure in athletes with ankle instability during lateral shuffling and running gait

This study evaluates foot pressure and center of pressure (COP) patterns in individuals with ankle instability during running and lateral shuffling. Eleven participants with ankle instability (AI) and 11 normal subjects (Normal) performed running and lateral shuffling tasks. The outcome measures were foot progression angle, peak pressure, and displacement of COP during stance phase. During running, the foot progression angle, that is, the angle of foot abduction, was lower in the AI group (Normal: 13.46° ± 4.45°; AI: 8.78° ± 3.91°), and the 1st metatarsal contact pressure (Normal: 0.76 ± 0.47 N/cm²·kg; AI: 1.05 ± 0.70 N/cm²·kg) and the 3rd metatarsal peak pressure were higher in the AI (Normal: 0.96 ± 0.60 N/cm²·kg; AI: 1.54 ± 0.68 N/cm²·kg). The medial‐lateral (M‐L) COP in the late‐stance phase of running for the AI group transferred faster from lateral to medial foot than the Normal group. For lateral shuffling, the AI group had greater peak pressure at the 1st (Normal: 0.76 ± 0.67 N/cm²·kg; AI: 1.49 ± 1.04 N/cm²·kg), 2nd (Normal: 0.57 ± 0.39 N/cm²·kg; AI: 0.87 ± 0.68 N/cm²·kg), 3rd (Normal: 0.70 ± 0.54 N/cm²·kg; AI: 1.42 ± 0.87 N/cm²·kg), and 4th (Normal: 0.52 ± 0.38 N/cm²·kg; AI: 1.12 ± 0.78 N/cm²·kg) metatarsal areas than the Normal group. The M‐L COP located more laterally from the early to mid‐stance phase in the AI compared with the Normal group. The findings suggest that COP displacement during lateral shuffle may be a factor in ankle instability while the foot progression angle during running may be a compensatory strategy.     

In-shoe pressure distribution in "unstable" (MBT) shoes and flat-bottomed training shoes: a comparative study

BACKGROUND: Footwear comfort in many clinical situations is dependent on the ability of the 'shoe' to redistribute plantar pressure. Offloading the metatarsal heads may be achieved by fitting an insole, but recently a new design of shoe with a curved under sole (Masai Barefoot Technology or "MBT shoe") has been advocated. The aim of this study was to directly assess the effect of such shoes on gait pattern. METHODS: Normal subjects were recruited and asked to walk sequentially in (a) flat-soled training shoes and (b) midfoot bearing shoes (MBT shoe). Mean and peak pressures in four anatomically defined areas of the foot, and the total area of sole contact were measured electronically by an in-shoe system (Pedar Ltd., UK). PRINCIPAL RESULTS: Standing in the Masai shoes resulted in a 21% lesser peak pressure under the midfoot and an 11% lesser peak pressure under the heel in comparison to the figures found when patients wore their training shoes. There was a 76% compensatory increase in pressure under the toes. In essence there was a significant shift in pressure towards the front of the foot.     

健康人体在跑步机上主、被动运动的差异性研究

目的对健康人体在跑步机上主、被动运动的生物力学及心肺功能进行对比研究。方法 25名健康成年志愿者在自研平面跑步机上分别进行3、7、10 km/h下主、被动模式的运动,对运动过程中的步态特征、关节角度、足底压力、耗氧量和心率进行对比分析。结果相同速度不同模式间对比,人体步态特征无显著差异(P0.05),而身体倾角、髋、膝、踝关节角度差异显著(P0.05);足底第一、三、五跖骨区域处压力峰值在不同模式间差异具有显著性(P0.05);主动模式下运动的耗氧量和心率显著高于被动模式(P0.05)。结论主动模式和被动模式跑步在运动学、足底压力以及心肺功能方面存在差异。