Footbed shapes for enhanced footwear comfort

A shoe wearer's comfort is related to the shape of the footbed of a shoe. Even though the footbed shape is important in footwear design, there exists no methodology to evaluate the existing guidelines used in last making. Thirty-two females participated in an experiment where heel seat length, heel seat inclination and heel height were investigated using the profile assessment device. The dependent variables were plantar pressure and perceived feeling of each participant. The results show that perceived feel is best for wedge angles of 4° and 5° at a heel height of 25 mm, 10° and 11° at a heel height of 50 mm and 16° and 18° at a heel height of 75 mm. A regression model was derived and this explained approximately 80% of the variation of perceived feeling with the contact area, peak plantar pressure and percentage of force acting on the forefoot region. Both heel wedge angle and heel seat length play an important role in the perceived feel of high-heeled shoes. This study, in relation to the load-bearing heel part of a shoe, highlights the importance of good footbed design. The findings can be used to design footwear with enhanced comfort.     

Professional footwear evaluation for clinical nurses

Epidemiological investigations indicate that nursing professionals experience a higher prevalence of musculoskeletal disorders (MSDs) than most other occupational groups. Most nursing activities require standing and walking for prolonged periods. Such job requirements may contribute to MSD problems in the lower extremities. Thus, wearing comfortable nursing shoes is essential to reduce the lower-extremity discomfort for clinical nurses. The objectives of this study are: (1) to evaluate three brands of commercially available nursing footwear and identify the important shoe features for adequate shoe support during nursing activities, and (2) to assess the effect of wearing compression hosiery by measuring the biomechanical, physiological, and psychophysical responses of test participants. The method of this study involved two phases. First, field observations were conducted to collect job demand data, including walking speed, and the ratios of walking, standing, and sitting. Second, an experiment was conducted to evaluate the functions of professional nursing footwear and examine the influence of compression hosiery on lower extremity discomfort relief. Measurements included electromyography (EMG) of the lower leg, joint range of motion (ROM) in the lower extremity, foot pressure, ground reaction force (GRF), and subjective discomfort ratings for the lower body and feet. Summarizing the findings of this study, comfortable footwear for nursing professionals should emphasize a footbed with arch support outside with 1.5 cm thickness of EVA materials in the metatarsal zone and heel height between 1.8 and 3.6 cm; this can minimize foot pressure distribution, impact force, and increase shin and ankle comfort. In addition, wearing compression hosiery is recommended to alleviate lower body and foot discomfort for clinical nurses.     

Effects of heel cushioning elements in safety shoes on muscle–physiological parameters

Safety shoe designs are primarily based on safety requirements. But all-day comfort should not be luxury: Heel strike associated impact loads on joints need to be compensated by active muscular effort and safety shoes should support this protective function of muscle activation. In 10 healthy men, 12 trunk and leg muscles were analyzed with surface electromyography. Subjects walked on a walkway while wearing different safety shoes with the test shoes being equipped with exchangeable cushioning heel inserts according to individuals' body weight. While wearing the optimally cushioned shoes the cumulative muscle activity per distance travelled dropped clearly compared to the regular safety shoes, demonstrating reduced muscular effort. Also, the heel strike associated amplitude peak of back muscles occurred earlier within the stride while wearing the test shoes. Thus weight-balanced cushioning heel inserts in safety shoes proved able to reduce muscle strain, logically delaying muscular fatigue and extending muscular joint protection.Relevance to industryAdjustable heel inserts in safety shoes are suited to improve the health status of employees by reducing muscular effort so that active joint protection can be prolonged.     

基于PWCG定位的FSVM评价高跟鞋舒适度

以高跟鞋为研究对象,针对目前以主观为主的高跟鞋舒适度测定方法缺乏定量描述、精确性欠佳等问题,提出了基于多边形加权重心(PWCG)定位的FSVM评价高跟鞋舒适度的方法,量化、精确测定高跟鞋的舒适度。提出的PWCG定位法解决压力传感器最佳放置位置的问题,利用基于压力传感器的足底压力采集平台采集足底在不同鞋跟高度时的压力分布情况,结合FSVM分类法对高跟鞋的舒适度进行定量、精确测定,并解决了舒适度测量中的小样本、非线性和泛化性问题。实验结果证明:该评价方法具有较高的可靠性和准确性,这对改善高跟鞋的压力舒适度问题,降低足底疾病概率和推动高跟鞋产业的发展都具有重要的理论与现实价值。     

Can an off-the-rack orthotic stiletto alter pressure and comfort scores in the forefoot,arch and heel?

The study sought to investigate whether an orthotic stiletto could modulate the pressure and comfort under the forefoot, arch and heel that stiletto wearers experience. Twenty-two women participated. We measured the peak pressure and pressure-time integral for orthotic stilettos with built-in metatarsal pad, heel cup and arch support; standard stilettos without inlays; and trainers. Comfort was recorded during 3 × 3 working days. The orthotic stiletto exhibited lower metatarsal head1 (MTH) and MTH2+3 and heel pressures than the standard stiletto (p < .01), and a long second metatarsal increased MTH2+3 pressure (p < .01). The comfort in the forefoot and heel was higher in the orthotic stiletto than in the standard one (p < .01), and comfort in the forefoot was correlated to the pressure-time integral of MTH2+3 (p = .03) and not peak pressure. Off-the-rack orthotic stilettos can notably reduce plantar pressures and improve forefoot and heel comfort during everyday use.

Practitioner Summary: Off-the-rack orthotic stilettos with built-in metatarsal pad, arch support and heel caps can lower the pressure under the heel and forefoot in comparison with a standard stiletto and can improve comfort during everyday use. Having a long second metatarsal is a risk factor for increased forefoot pressure.     

Biomechanical effects of wearing high-heeled shoes

A survey of 200 young women wearing high-heeled shoes indicated frequent complaints of leg and low back pain. Consequently, an empirical study examined the biomechanical effects of three heel heights (0, 4.5, and 8 cm), while standing stationary and while walking in five, healthy, young women. Four major biomechanical effects were observed. As heel heights increased, the trunk flexion angle decreased significantly. Similarly, tibialis anterior EMG, low back EMG and the vertical movement of the body center of mass increased significantly while walking with high-heeled shoes. Due to these added stresses, wearing of high heels should be avoided.

Relevance to industry

In addition to the normal physical job stresses, women workers may experience additional biomechanical stresses placed on them by fashion demands such as high heels. All these effects can significantly increase discomfort levels in those wearing high heels.     

Classification and mass production technique for three-quarter shoe insoles using non-weight-bearing plantar shapes

We have developed a technique for the mass production and classification of three-quarter shoe insoles via a 3D anthropometric measurement of full-size non-weight-bearing plantar shapes. The plantar shapes of fifty 40-60-year-old adults from Taiwan were categorized and, in conjunction with commercially available flat or leisure shoe models, three-quarter shoe-insole models were generated using a CAD system. Applying a rapid prototype system, these models were then used to provide the parameters for manufacturing the shoe insoles. The insoles developed in this study have been classified into S, M and L types that offer user-friendly options for foot-care providers. We concluded that these insoles can mate tightly with the foot arch and disperse the pressure in the heel and forefoot over the foot arch. Thus, practically, the pressure difference over the plantar region can be minimised, and the user can experience comfort when wearing flat or leisure shoes.     

Relationship between posture and lifting capacity

This study investigates the effect of changes in posture caused by wearing high-heeled shoes on the maximum lifting capacity. Nine female college students, ages 20 to 25 years, participated in this study. Three heel heights (flat, 5 cm and 7.6 cm), two lifting heights (floor to knuckle and knuckle to shoulder), and lifting frequency of 4 per minute were examined. The results indicate that a significant difference exists between MAWOL with flats and that with 7.6 cm heels for both lifting heights. Subjects lifted 21.5% less weight using 7.6 cm heels than wearing flats. No significant difference was found between MAWOL with flats and 5 cm high heels. In addition, in evaluating the tasks subjectively, the subjects reported that they experienced a stress ontheir legs when lifting with 5 cm and 7.6 cm high-heeled shoes. The conclusion of this study indicates that a change in posture affects lifting capacity, and individuals should adjust their predetermined MAWOL while wearing high-heeled shoes.     

Female gait patterns: The influence of footwear

The two horizontal orthogonal ground reaction forces, mediolateral (Fx) and antero-posterior (Fy), together with limb segment displacements, were recorded simultaneously during gait from 24 female subjects aged 18–29 years. Recordings were made for each subject barefoot and when wearing each of four different pairs of shoes: soft-soled, rigid-soled, medium- and high-heeled. The results showed a trend for increasing lateral stability with increasing heel height and decreasing ground contact area. This.was reflected in decreasing mean values for defined ground reaction force peaks in the medio-lateral direction at heel strike and at toe off. Limb segments displacements tended to increase with decreasing heel height and increasing shoe-ground contact area, being greatest when subjects were wearing pumps, i.e. flexible-soled, no-heeled shoes.     

Use of pressure insoles to compare in-shoe loading for modern running shoes

The primary objective of this paper was to compare in-shoe loading for different models of running shoe using measurements of force distribution. It was hypothesised that a shoe designed with minimal focus on cushioning would demonstrate significantly higher peak forces and rates of loading than running shoes designed with cushioning midsoles. Loading was compared using in-shoe peak forces for six footwear conditions. It was found that peak rate of loading at the heel provided clear distinctions between shoes. In support of the study hypothesis, the shoe with minimal focus on cushioning had a significantly higher rate of loading than all but one of the other test shoes. Data collected for midfoot and forefoot areas of the foot highlighted the importance of considering loading across the foot surface. The results of the present study demonstrate that pressure insoles provide a useful tool for the assessment of loading across the foot plantar surface for different footwear conditions. There are numerous models of running shoe for individuals to select from, with limited information available regarding the performance of the shoes during running. The current study demonstrates differences in loads across the foot plantar surface during running, indicating differences in performance for different footwear models.     

A qualitative study on the comfort and fit of ladies' dress shoes

The perceived differences between comfortable and uncomfortable shoes and the fit preferences in the different regions of ladies' shoes were explored. Twenty Hong Kong Chinese females participated in the study. Each participant wore and rated the different aspects of their own comfortable and uncomfortable shoes. The Wilcoxon signed rank tests showed significant differences in ten perceived characteristics between the comfortable and uncomfortable shoes. Among the ten were tactile, auditory and olfactory sensations. The ten items reliably (Cronbach alpha>0.9) distinguished between comfortable and uncomfortable shoes. There were no significant differences between comfortable and uncomfortable shoes for aesthetic-related characteristics. Further analysis on the fit ratings showed a significant impact on the fit preferences in the Toe region (p<0.0001), Metatarsophalangeal (MPJ) region (p<0.0001), Arch region (p=0.002) and Ingress/egress opening (p<0.001). Knowing the preferred type of fit can help establish a specification for comfortable shoes and also brings out the criteria that a comfortable shoe does not necessarily have the same perceived fit in every region of a shoe.     

Use of pressure insoles to compare in-shoe loading for modern running shoes

The primary objective of this paper was to compare in-shoe loading for different models of running shoe using measurements of force distribution. It was hypothesised that a shoe designed with minimal focus on cushioning would demonstrate significantly higher peak forces and rates of loading than running shoes designed with cushioning midsoles. Loading was compared using in-shoe peak forces for six footwear conditions. It was found that peak rate of loading at the heel provided clear distinctions between shoes. In support of the study hypothesis, the shoe with minimal focus on cushioning had a significantly higher rate of loading than all but one of the other test shoes. Data collected for midfoot and forefoot areas of the foot highlighted the importance of considering loading across the foot surface. The results of the present study demonstrate that pressure insoles provide a useful tool for the assessment of loading across the foot plantar surface for different footwear conditions. There are numerous models of running shoe for individuals to select from, with limited information available regarding the performance of the shoes during running. The current study demonstrates differences in loads across the foot plantar surface during running, indicating differences in performance for different footwear models.     

How do we fit underground coal mining work boots?

Abstract

Acceptable footwear fit, particularly width, is subjective and vaguely quantified. Proper shoe fit is important because it affects both comfort and the potential to prevent injury. Although mismatches between the feet of underground coal miners and their internal boot dimensions are known, no research has been undertaken to determine the impact of these mismatches on worker perceptions of fit, comfort and pain. This study aimed to quantitatively assess mining work boot fit relative to underground coal miners’ subjectively rated work boot fit and comfort, reported foot problems, lower limb pain and lower back pain in order to develop evidence-based work boot fit recommendations. Traditional footwear fitting methods based predominantly on foot length are insufficient for underground coal mining-specific footwear. Instead, fit at the heel, instep and forefoot must be considered when fitting underground coal mining work boots, in conjunction with the traditional length measurement.Practitioner summary: Underground coal miners report their work boots fit but are uncomfortable. This study assessed actual fit relative to perceived fit, comfort, foot problems, lower limb pain and lower back pain of 197 miners. Fit at the heel, instep and forefoot must be considered when fitting mining work boots.     

Effects of surface characteristics on the plantar shape of feet and subjects' perceived sensations

Orthotics and other types of shoe inserts are primarily designed to reduce injury and improve comfort. The interaction between the plantar surface of the foot and the load-bearing surface contributes to foot and surface deformations and hence to perceived comfort, discomfort or pain. The plantar shapes of 16 participants’ feet were captured when standing on three support surfaces that had different cushioning properties in the mid-foot region. Foot shape deformations were quantified using 3D laser scans. A questionnaire was used to evaluate the participant's perceptions of perceived shape and perceived feeling. The results showed that the structure in the mid-foot could change shape, independent of the rear-foot and forefoot regions. Participants were capable of identifying the shape changes with distinct preferences towards certain shapes. The cushioning properties of the mid-foot materials also have a direct influence on perceived feelings. This research has strong implications for the design and material selection of orthotics, insoles and footwear.     

Inter-joint sharing of total support moments in the lower extremities during gait in narrow-heeled shoes of different heights

The study aimed to investigate the influence of the base and height of shoe heels on the total support moment (Ms) and individual joint contributions during gait. Fifteen healthy females walked barefoot and with narrow-heeled shoes (heel heights: 3.9, 6.3 and 7.3 cm) while kinematic and kinetic data were measured. Compared with the barefoot condition, the subjects maintained unaltered Ms in the sagittal plane in shod conditions. This was achieved by increasing the knee extensor moment to compensate for the diminished ankle plantarflexor moments in medium and high heel conditions. In the frontal plane, subjects in shod conditions had to sustain an increased Ms for balance control during late single-leg stance with increased knee abductor and ankle pronator moments as a result of the reduced base of the heels. The results will be helpful for future shoe designs to reduce fall risks and prevent relevant musculoskeletal problems     

Ethnic differences in forefoot shape and the determination of shoe comfort

The kinanthropometric aspects of comfort of fit of sport shoes has not been subjected to any great scrutiny. It is suggested that comfort of fit is largely determined by the match of foot shape to shoe shape and consequently there is a need for normative data that describe foot shape, dimension and proportion for discrete populations. A study of 708 second generation Caucasian N. American (NA) and 513 Japanese and Korean (JK) male subjects was conducted to determine normative data with respect to forefoot shape and dimension. A series of 2 height, 7 length, 1 breadth and 1 girth measures of the right foot bearing full body weight was recorded using a modified Mitutoyo digital caliper interfaced with a micro-processor. Substantial differences were noted in the incidence of digital patterning. The relative proportion of digital patterns I(l>2>3>4>5) and II (2 > 1 > 3 > 4 > 5) were NA 76.09%, 23.91%; JK 50.80% and 49.20% respectively. The distance between the pternion and the distal extremity of the second digit expressed as a percentage of die maximum foot lengdi (MFL) was found to be 98.60% (NA) and 99.60% (JK). In addition, the distance between the pternion and the distal extremity of the fifth digit relative to MFL was 82-60% (NA) and 85.00% (JK). The implication of these data is that the anterior margin of the JK foot makes a less acute angle with the long axis of the foot than the NA population. Additional information with respect to foot breadth leads to the conclusion that the shape of the JK forefoot differs from that of the NA, with the implication that unique shoe lasts for both populations are required for optimal shoe comfort.     

Effects of high heeled shoes wearing experience and heel height on human standing balance and functional mobility

This study aimed to examine the effects of high heeled shoes (HHS) wearing experience and heel height on human standing balance and functional mobility. Thirty young and healthy females (ten experienced and twenty inexperienced HHS wearers) participated in a series of balance tests when they wore shoes of four different heel heights: 1 cm (flat), 4 cm (low), 7 cm (medium) and 10 cm (high). Experimental results show that regardless of the wearing experience, the heel elevation induces more effort from lower limb muscles (particularly calf muscles) and results in worse functional mobility starting at 7 cm heel height. While the heel height increased to 10 cm, the standing balance also becomes worse. Experienced HHS wearers do not show significantly better overall performance on standing balance and functional mobility than inexperienced controls, even though they have better directional control (76.8% vs. 74.4%) and larger maximum excursion (93.3% vs. 89.7%). To maintain standing balance, experienced wearers exert less effort on tibialis anterior, vastus lateralis and erector spinae muscles at the cost of more intensive effort from gastrocnemius medialis muscle.     

Effect of various foot wedge conditions on the electromyographic activity of lower extremity muscles during load lifting

The level of muscle activity can be decreased with optimized foot wedge condition. The aim of this study was to evaluate the effect of different foot wedge conditions on the activity of selected lower extremity muscles during load lifting. Nine able‐bodied male subjects participated in this study. Electromyography activity of the vastus medialis (VM), vastus lateralis (VL), medialis gastrocnemius (MG), and soleus (SOL) muscles was recorded during dynamic load lifting using the squat technique in 5 conditions: i) non‐wedge (NW), ii) 1 cm heel height increasing (PW1), iii) 3 cm heel height increasing (PW3), iv) 1 cm in front of the feet (AW1), and v) 1 cm inside the feet (MW1). The results showed that the VM activity decreases in the MW1 compared to other conditions and significantly compared to the PW1 and PW3 conditions (p < .05). Decreases in the VL activity in the AW1 as well as in descending and ascending phases of MW1 were observed (p < .05). Also in the descending phase, the SOL activity in AW1 decreased significantly compared to NW condition (p < .05). However, there was no significant difference in MG activity between different conditions (p > .05). It seems that placing wedges in the anterior and medial area of the feet may decrease quadriceps muscles activity and probably can delay reaching time to fatigue during load lifting. These findings may be helpful in designing special shoes for ergonomics fields and work environments.     

Sweat distribution and perceived wetness across the human foot: the effect of shoes and exercise intensity

Abstract

This study investigates foot sweat distribution with and without shoes and the relationship between foot sweat distribution and perceived wetness to enhance guidance for footwear design. Fourteen females performed low-intensity running with nude feet and low- and high-intensity running with shoes (55%VO_2max and 75%VO_2max, respectively) on separate occasions. Right foot sweat rates were measured at 14 regions using absorbent material applied during the last 5?min of each work intensity. Perceptual responses were recorded for the body, foot and four foot regions. Foot sweat production was 22% greater nude (p?<?.001) and with shoes did not increase with exercise intensity (p?=?.14). Highest sweat rates were observed at the medial ankle and dorsal regions; lowest sweat rates at the toes. Perceptions of wetness and foot discomfort did not correspond with regions of high sweat production or low skin temperature but rather seemed dominated by tactile interactions caused by foot movement within the shoe.

Practitioner summary: This study provides a detailed view of foot sweat distribution for female runners with and without shoes, providing important guidance for sock and footwear design. Importantly, perceptions of wetness and foot discomfort did not correspond with areas of high sweat production. Instead tactile interactions between the foot, sock/shoe play an important role.

Abbreviations: VO_2max: maximal oxygen consumption; HR: heart rate; RH: relative humidity; GSL: gross sweat loss; Nude-I1: without socks and shoes, low intensity running; Shod-I1: with socks and shoes, low intensity running; Shod-I2: with socks and shoes, high intensity running     

Association between objective and subjective measurements of comfort and discomfort in hand tools

In the current study, the relationship between objective measurements and subjective experienced comfort and discomfort in using handsaws was examined. Twelve carpenters evaluated five different handsaws. Objective measures of contact pressure (average pressure, pressure area and pressure-time (P-t) integral) in static and dynamic conditions, muscle activity (electromyography) of five muscles of the upper extremity, and productivity were obtained during a sawing task. Subjective comfort and discomfort were assessed using the comfort questionnaire for hand tools and a scale for local perceived discomfort (LPD). We did not find any relationship between muscle activity and comfort or discomfort. The P-t integral during the static measurement (beta=-0.24, p<0.01) was the best predictor of comfort and the pressure area during static measurement was the best predictor of LPD (beta=0.45, p<0.01). Additionally, productivity was highly correlated to comfort (beta=0.31, p<0.01) and discomfort (beta=-0.49, p<0.01).