An explorative qualitative study to determine the footwear needs of workers in standing environments

Background: Many work places require standing for prolonged periods of time and are potentially damaging to health, with links to musculoskeletal disorders and acute trauma from workplace accidents. Footwear provides the only interaction between the body and the ground and therefore a potential means to impact musculoskeletal disorders. However, there is very limited research into the necessary design and development of footwear based on both the physical environmental constraints and the personal preference of the workers. Therefore, the purpose of this study is to explore workers needs for footwear in the ‘standing’ workplace in relation to MSD, symptoms, comfort and design. Method: Semi-structured interviews were conducted with participants from demanding work environments that require standing for high proportions of the working day. Thematic analysis was used to analyse the results and gain an exploratory understanding into the footwear needs of these workers. Results: Interviews revealed the environmental demands and a very high percentage of musculoskeletal disorders, including day to day discomfort and chronic problems. It was identified that when designing work footwear for standing environments, the functionality of the shoe for the environment must be addressed, the sensations and symptoms of the workers taken into account to encourage adherence and the decision influencers should be met to encourage initial footwear choice. Meeting all these criteria could encourage the use of footwear with the correct safety features and comfort. Development of the correct footwear and increased education regarding foot health and footwear choice could help to reduce or improve the effect of the high number of musculoskeletal disorders repeatedly recorded in jobs that require prolonged periods of standing. Conclusion: This study provides a unique insight into the footwear needs of some workers in environments that require prolonged standing. This user based enquiry has provided information which is important to workplace footwear design

Investigating footwear biomechanics concepts in ‘health and well-being’ footwear

Health and well-being’ footwear positions itself in the footwear market between high street footwear and specialist therapeutic footwear. Manufacturers in this footwear category promote benefits when compared with standard footwear. However, the full exploration and validation of such proposed benefits requires scientific exploration through the application of footwear biomechanics concepts and techniques. The studies herein were undertaken to assess these biomechanical concepts in ‘health and well-being’ footwear, particularly in FitFlopTM footwear. The studies are experimental studies with repeated measures designs. A total of 128 individual participants volunteered, 28 of which were included in two publications. Variables were quantified using an in-shoe plantar pressure measurement system (with a bespoke insole), electromyography, 3D motion capture, force plates, accelerometers, a modified questionnaire and a custom-made mechanical drop-test device. The research identified that ‘health and well-being’ footwear can be manipulated to increase shock absorption, namely reducing the heel-strike transient magnitude (-19%) compared with a flip-flop. ‘Health and well-being’ footwear does induce instability at specific phases of the gait cycle, which is specific to the outsole shape of the footwear. For example the MBT shoe increased muscle activity relating to controlling sagittal plane motion. The biomechanics of gait are also altered compared to standard footwear styles, such as reducing the frontal plane motion of the foot in stance (-19%) and the magnitude (-86%) and duration (-98%) of gripping with the Hallux in swing compared with a flip-flop. The tested ‘health and well-being’ footwear was subjectively rated equally as comfortable as a control shoe with increased regional pressures in the midfoot (≈25%) and decreased peak pressures in the heel (-22%). Therefore ‘health and well-being’ footwear may influence the biomechanics of wearers however further exploration of meaningful differences and individual population differences is required. The studies emphasise the importance and relevance of testing walking, as well as running, footwear to the wider footwear biomechanics field and demonstrate how this may be integrated into research and development processes within a footwear company

The effects of heel height, shoe volume and upper stiffness on shoe comfort and plantar pressure

The research in this thesis investigated the independent effects of changing heel height, forefoot shoe volume and upper material stiffness on plantar pressures and comfort in ladies raised heel shoes. Plantar pressure is widely associated with comfort and foot pain including conditions such as subchondral bone microfractures, cartilage degeneration, osteoarthritis, hallux valgus, plantar calluses, metatarsalgia, morton’s neuroma, and hammer toe. Reducing peak plantar pressure at localised foot regions is therefore an aspiration of footwear manufacturers and health professionals alike. As a precursor to the primary investigations, protocols for measuring plantar pressure were investigated. Specifically, how long it takes for a participant to acclimatise to new footwear and how many steps must be measured to provide valid plantar pressure data are research design issues not thoroughly resolved by prior research. In the first study within this thesis it was found that 166 steps per foot were required to acclimatise to unfamiliar footwear. Also, that data from 30 steps should be collected to ensure sufficient data for a representative step could be accurately calculated (within error of +/-2.5%) assumedThe second study investigated the effects of incremental increases in heel height and upper material stiffness on comfort and plantar pressure. It was found that an increase in heel height of 20mm was required for a significant 19% increase in plantar pressure at MTP1 in shoes which have a heel height under 55mm. A significant increase in pressure was observed with just a 10mm increase in heel height for shoes over 55mm. Similar, though smaller, effects were observed for perceived comfort in different heel heights. The third study investigated the effects of shoe volume and upper stiffness on comfort and plantar pressure. It was found that an increase in shoe volume increased the pressure at the MTP1 and reduced it at the heel. There was also a volume, the medium volume shoe, which clearly produced the significantly lowest pressure at the MT24 (275kPa medium shoe compared to 289kPa and 305 kPa in the smallest and largest volumes respectively). A significant interaction between shoe volume and material stiffness was also observed: when the material stiffness is changed the amplitude of the effect due to volume is magnified. Of the three footwear features investigated heel height has the greatest significant effect on both comfort (74% increase in overall discomfort for 35mm to 75mm heel height) and plantar pressure (33% increase at MTP1 between 35 and 75 mm heel height), followed by shoe volume then upper stiffness. There was a clear relationship between plantar pressure and comfort and the results suggest that shoes with an effective heel height over 55mm should be considered different from those with heel height less than 55mm. This serves to define a “high heeled“shoe.To ensure that set measurements could be defined investigations into the effects of heel height were completed with only one shoe size. Thus for other shoe sizes scaling may be required. The results of this thesis will improve the quality of future investigations because it has provided guidelines on the required number of steps to acclimatise to unfamiliar footwear, and the number of steps required to produce an average representative step. Also, to the benefit of researchers, the results of this thesis have highlighted the difficulty in controlling features of footwear such as the stiffness of the upper material whilst simultaneously demonstrating the importance of controlling this feature. For both shoe manufactures and research these results have shown the effect of a systematic increase in heel height which has enabled the first pressure and comfort based definition of a high heeled shoe. From this information designers will have a greater understanding of how their designs will have an effect on the plantar pressure and comfort experienced by the wearer

A research on footwear and foot interaction through anatomy and human engineering

Thesis (Master)--Izmir Institute of Technology, Industrial Design, Izmir, 2005Includes bibliographical references (leaves: 144)Text in English; Abstract: Turkish and Englishxix, 155 leavesThe main purpose of this thesis is to examine the footwear design from the human engineering point of view. Traditionally, the concern of the designer has mostly concerned to the form in footwear design field, but user and environment-conscious designer should think about the value and compatibility of the footwear to experience comfort, performance, safety and satisfaction during use. To develop the "Footwear Design" in a human centered way, the designer should be able to synthesis the datum of design that had been analyzed from the "Human Engineering. point of view and able to assess or evaluate which design solution is better and compatible for human mobility.The basic aim of this study is to help designers to comprehend the conceptual infrastructure of footwear and foot interaction such as anatomy, anthropometry, biomechanics, physical characteristics, and ergonomics.One of the main purposes of chapter 2 is to examine the every aspect of industrial product design from the human engineering point of view and in this context, the definition of footwear design elements.In chapter 3, the foot structure is analyzed from the anatomical, morphological and biomechanical point of view with respect to foot-footwear interaction and human engineering and the Failings of modern footwear design and its discordant features and detrimental manner for the foot natural characteristics are examined to attract the attention of the designers for perceiving the responsibility that they have.In chapter 4, there are two main sections which contain fundamental design criteria through foot- footwear interaction and ergonomic considerations. Then the innovative and affirmative characteristic of modern footwear design is analyzed to encourage the designer to design the better products to drive the footwear design to new heights with respect to human nature using appropriate materials and appropriate forms

The impact of footwear choice on foot biomechanics in young adults with considerations to the potential risk of developing foot pathology

Foot pain and pathology can be disabling leading to more complex orthopaedic complaints over time. Footwear is often attributed as a significant factor in the development and persistence of foot pain, yet little is known about the impact everyday footwear choice has on the development of these pathologies and foot biomechanics. The aim of this collection of work is to assess the impact footwear choice has on foot biomechanics. A mixed methods approach has been employed across various publications to investigate the following; choices made when purchasing footwear, the impact footwear structure and styling has on foot mechanics and comfort and the effect of unstable shoes on muscle function. The publications employed literature reviews, qualitative questionnaires, repeated measures and quasi-experimental designs to address the research questions. There is a paucity of research regarding the effects that everyday footwear have on the feet of healthy individuals. A flat ballet pump was found to be the primary shoe of choice for young females with the colour of trainers being selected by sport science students. Altered physical characteristics of the shoe caused elevated dorsal and plantar foot pressure, impaired comfort and altered function. Fashionable exercise shoes were shown to demonstrate a varied effect on muscle activity. The availability of suitably fashionable and functional footwear appears to be severely limited leading to consumers purchasing inappropriate and ill-fitting footwear that may contribute to foot pathology. An extensive review of design, properties and manufacture with specific consideration to pathology in the footwear industry is recommended to improve footwear choice. The publications presented add new knowledge when evaluating consumer choice of footwear and the potentially adverse impact popular female fashion shoes have on foot biomechanics. The results also contribute to a wider understanding of the impact everyday footwear has on foot pathology and help in the application of footwear related treatment and rehabilitation plans

The specification and evaluation of personalised footwear for additive manufacturing

The personalisation of footwear offers advantages not only for runners, but to anyone who wishes to become more active. Additive manufacturing (AM) technology has the potential for making footwear personalisation economically feasible by allowing direct manufacture from CAD models and its tool-less capability. This thesis aims to develop and explore the process of footwear personalisation using AM and evaluates such footwear in terms of discomfort and biomechanics. To start to explore this process a repeated measures pilot study was conducted. Six recreational runners had anthropometric measurements of the foot taken and the plantar surface of both feet scanned. From the scans and measurements, personalised glove fit insoles were designed and manufactured using AM. Participants were then fitted with footwear under two experimental conditions (control and personalised), which were compared in terms of discomfort, performance and biomechanics. The findings of this pilot confirmed the feasibility of the personalisation process. A longitudinal study was then conducted to evaluate the short and medium term use of personalised footwear in terms of discomfort and biomechanics. A matched pairs study design was utilised and 38 recreational runners (19 pairs) were recruited. Control (generic shape) and personalised geometry insoles were designed and manufactured using AM. The participants wore the footwear each time they went running for a 3-month period. They also completed an Activity Diary after each training session and attended 4 laboratory sessions during this period. The results showed significantly lower discomfort ratings in the heel area and for overall fit with the personalised insoles. However, discomfort was reported under the arch region for both conditions (supported by the Activity Diary), indicating that the foot scanning position and material may need modifying. With regard to the biomechanics, the personalised insoles also led to significantly lower maximum ankle eversion and lower peak mean pressure under the heel, which are potentially positive effects in terms of reducing injury risk. A case study is then reported which explored foot capture using a dynamic scanner for the design and manufacture of insoles using AM. Through the development of four insoles, it was found that the selection and manipulation of the scan data from the series of frames generated during ground contact were the most demanding elements of the process. Finally, recommendations and guidance are given for the footwear personalisation process (foot scan position, anthropometry, insole design and AM), together with its potential benefits and limitations

The kinematic effects of three quarter and full length foot orthoses on anterior knee pain sufferers when walking and descending stairs

Background: Patellofemoral pain is a common disorder whose aetiology is complex often being described as multifactorial, increased load of the patellofemoral joint is often attributed to foot function. Foot orthoses are commonly prescribed for this condition; however the mechanisms by which they work are poorly understood. Previous studies using single segment foot models have hypothesised that it may be control of the midfoot which hold the key to understanding orthotic control. Over the last decade biomechanical analyses has advanced so it has become possible to divide the foot into segments, however no previous studies have investigated the use of orthoses on different segments of the foot when shod. The overall aim of this study was to investigate the differences seen in the kinematics and kinetics of the lower limb between a patellofemoral pain group and a group of normals when using a standardised orthosis prescription during walking and descending a step. Method: Initially fifteen healthy subjects had foot orthoses moulded to their feet, they were asked to walk at a self-selected pace and complete a 20cm step down; comparisons were made between sandals and shoes, plus two different orthoses. Kinematic and kinetic data were recorded using 10 Oqus cameras and 4 AMTI force platforms. The shoe data from the 15 healthy subjects was re-analysed and used as a control group to compare against 15 subjects diagnosed with patellofemoral pain. The foot was modelled using the calibrated anatomical systems technique (CAST) fixing the marker set directly on the feet and shoes of normal subjects which permitted comparisons of excursions between the shoes and sandals and the effects of the orthoses. Results 1: Similar changes in the pattern of movement were seen between the shoe and the sandals conditions with and without the orthoses; the shoes reduced the excursions recorded except the transverse plane of the rearfoot. At the knee maximum extension was increased and maximum flexion at toe off was reduced by the orthoses. Initial Conclusions: Expectedly the shoes reduced the range of motion over the sandal condition in most planes; however the similar effects seen with the orthoses in both types of footwear suggesting it was acceptable to use shoes in the later study. Results 2: Significant differences were seen between the healthy subjects and the patellofemoral pain subjects at the foot and the knee. Both orthoses produced statistically significant results at the foot. In addition there was a significant reduction in the knee coronal plane moment range during the forward continuum phase of step down; this was attributed to a change in the ground reaction force as there were no changes reported in the kinematics of the knee. Conclusions: The method of placement of the markers was able to detect small changes within the foot segments. This study identified potentially important differences between the patellofemoral pain subjects and the normals in both the knee and foot segments. However due to the lack of pain during the walking and step down trials it could not be determined if the changes were due to pain avoidance mechanisms or if they were causative factors. Many of the changes produced by the orthoses tended to be local to the foot, except for the knee coronal plane moment range during the forward continuum phase of step down. To the authors knowledge this work is unique in its investigation of the motion of foot segments while shod and confirmed the clinically held belief it is essential to consider footwear when prescribing orthoses to patients. The use of foot mechanics could be of interest to further research and may help to define sub-populations within this condition

A Biomechanical Assessment of Gait Patterns and Risk of Associated Overuse Conditions among Mature Female Runners

Due to a proliferation of health and social advantages, the popularity of running among the more mature members of the female population is expanding steadily. However, with both age and gender acting as possible risk factors, the incidence of running related injuries and associated conditions is high among this group. With the predominance of debilitating conditions such as knee joint osteoarthritis acting at the knee joint, knowledge of lower limb biomechanics during running will provide insight into possible risk factors and potential management strategies. Three biomechanical and one magnetic resonance imaging study focussed on the specific running gait of mature females and the effect of footwear on lower limb joint kinematics and loading. The biomechanical studies used synchronised ground reaction force and lower extremity kinematic data to provide three dimensional running data and knee moments for each female. The long term study objectives were to 1) determine whether the running gait of mature females could be a predisposing factor to injuries and conditions at the knee joint, and 2) determine if changes in footwear could modify biomechanical variables associated with the development of injuries and overuse conditions among this group. In Study One, a direct comparison of mature and young female running gait was used to identify any biomechanical movement characteristics specific to the mature group that could predispose to injuries and debilitating conditions. It was found that rearfoot eversion, ankle dorsiflexion, knee internal rotation, and knee external adductor moment that are associated with increased loading of the lateral knee joint and possible medial knee joint osteoarthritis development, were significantly higher among the mature females compared to the younger group (p<0.05). A common management strategy for running related conditions is the adaption of footwear. Therefore Study Two investigated the effect of a motion control running shoe on the running gait of young and mature females, with a specific focus on the variables associated with knee joint injury and osteoarthritis development. The results showed a motion control shoe to reduce certain biomechanical variables (rearfoot eversion and knee internal rotation) associated with mature female runners. However, one variable (knee external adductor moment) commonly associated with increased medial knee loading and osteoarthritis development, remained high among the mature females. One specific method used to reduce the knee external adductor moment, is the implementation of a lateral wedge in running shoes. Therefore, Study Three assessed the singular effects of a medial wedge, a lateral wedge, and then the effect of an orthotic combining both interventions on the running gait of mature females. Results demonstrated non significant changes in any kinematic variable with the medial or lateral wedge, although the lateral wedge was shown to reduce the knee external adductor moment. The orthotic intervention however produced significant reductions in rearfoot eversion, knee internal rotation, and knee external adductor moment previously found to be high among mature female runners. Although all mature females studied had previously been characterised as free from symptoms of knee injury or osteoarthritis, a final investigation was undertaken to assess the condition of the knee joint (Study Four). Magnetic resonance imaging scans of the knee were taken for ten of the mature females. Results indicated that eight out of the ten females had early stage osteoarthritis present, with an average 79% of features presenting on the medial side of the knee joint. Additionally, there was a strong positive correlation between knee osteoarthritis and the knee external adductor moments measured in the ongoing biomechanical study (Study Three). These studies have shown that the running gait of mature females is significantly different to that of younger female runners, and could predispose the mature group to injury and knee osteoarthritis development. The trends in kinematic adaption to a motion control shoe have shown promising results, and indicated the potential for footwear to reduce rearfoot eversion and knee internal rotation among mature female runners. However, a specific orthotic, incorporating both medial and lateral support has been found to reduce biomechanical features of gait associated with overloading at both the medial and lateral knee joint. The positive correlation between the knee adductor moment and signs of osteoarthritis for an asymptomatic population suggests that the knee adductor moment may be a useful predictive tool for identifying female runners at risk of osteoarthritis development