title: Exploring interindividual running economy responses to advanced footwear technology shoes across a range of variables: A quantitative study

authors: Cumming, Christiaan

abstract: Abstract
In the past decade, the running landscape has changed due to advanced footwear technology (AFT) being imbedded in running shoes. While AFT shoes have been shown to improve running economy (RE) on average, little is known about the factors that explain the large interindividual variability in RE response. Therefore, this study aimed to investigate the interindividual variability in RE response to AFT and identify potential predictors of this variability using quantitative methods. This thesis considered participant characteristics, anthropometric measures, neuromuscular measures, and subjective perceptions as potential factors underpinning interindividual variability.
This thesis is separated into three chapters. Chapter One is a brief review on AFT, their components, and their influence on RE and performance, as well as the observed interindividual variability in AFT shoe responses and the factors proposed to mediate this variability. AFT shoes have been designed to improve RE and include thick lightweight resilient and compliant foams, stiff elements embedded in the foam, and curved shoe geometry. Research has explored how these components may contribute to RE improvements and has proposed various factors that may explain the interindividual variability, such as running speed, training level, sex, leg length, body mass, shoe size, and plantarflexion muscle-tendon unit properties. Comparing the characteristics of responders to non-responders and exploring relationships between these characteristics and RE responses can assist in identifying runners more likely to benefit from running in AFT.
Chapter Two presents an experimental study using a cross-sectional, repeated-measures design.  A heterogenous sample of sixty-four participants (32 males, 32 females) of varying running levels, experience, age, and anthropometric characteristics completed two laboratory sessions between two and seven days apart. The first included baseline information and participant characteristics for anthropometric, neuromuscular measures, and maximal oxygen uptake. The second session served as the experimental phase, during which RE variables were evaluated in the two different shoe conditions: Salomon S/Lab Phantasm 2 (AFT) and Salomon Aero Glide 2 (CONTROL). RE was measured over four 6-minute trials in an AFT and a CONTROL shoe, allocated in a randomised, crossover order. Descriptive statistics (means ± SD), inferential comparisons (paired samples t-tests, Chi square, and Fishers exact), and Pearson’s correlation coefficients were calculated to compare between responders and non-responders to AFT shoes and explain AFT shoe response. The mean improvement in RE (expressed in terms of oxygen consumption) was 4.13 ± 1.6% when wearing AFT compared to CONTROL shoes, with individual responses ranging from -2.62% to 11.01%. From all the variables collected, only gastrocnemius medialis (GM) stiffness normalised to leg length was significantly different (p = 0.046) between groups, with responders exhibiting greater GM stiffness (329.8 ± 36.6 N/m²) compared to non-responders (296.4 ± 47.3 N/m²). No other between-group differences were statistically significant. Two variables were significantly and moderately correlated to RE response, where greater navicular drop (r = 0.31, p = 0.012) and greater GM stiffness (normalised to leg length) (r = 0.35, p = 0.005) were linked to greater RE benefits from running in AFT shoes. Additionally greater gear ratio (r = 0.26, p = 0.040) and lower standing plantarflexion isometric strength (normalised to body weight) (r = -0.26, p = 0.041) displayed significant and small correlations with improvements in RE when running in AFT shoes. A multiple linear regression including standing plantarflexion isometric strength, navicular drop, gear ratio, and GM stiffness (normalised to leg length) explained 27% of the variance in our AFT RE responses (R² = 0.2731, adjusted R² = 0.223), with GM stiffness being the most important factor (B = 0.014, p = 0.015). 
Lastly, Chapter Three summarises the findings, strengths, limitations, and recommendations for future research. This research provides further insight into interindividual variability in RE responses to AFT, showing not all runners benefit equally from AFT shoes. Therefore, runners should be aware that they may not improve their RE via AFT, however, individuals with greater GM stiffness, navicular drop, and static ankle gear ratio, and with lower standing plantarflexion isometric strength may benefit to a greater extent from AFT shoe wear. These factors may help guide more personalised footwear selection and prescription. Future research should investigate whether training interventions that modify these characteristics can enhance responses to AFT footwear and examine how other biomechanical variables, such as foot strike patterns or flight times, may interact with RE responses.

text: Exploring interindividual running economy responses to advanced footwear technology shoes across a range of variables: A quantitative study Abstract
In the past decade, the running landscape has changed due to advanced footwear technology (AFT) being imbedded in running shoes. While AFT shoes have been shown to improve running economy (RE) on average, little is known about the factors that explain the large interindividual variability in RE response. Therefore, this study aimed to investigate the interindividual variability in RE response to AFT and identify potential predictors of this variability using quantitative methods. This thesis considered participant characteristics, anthropometric measures, neuromuscular measures, and subjective perceptions as potential factors underpinning interindividual variability.
This thesis is separated into three chapters. Chapter One is a brief review on AFT, their components, and their influence on RE and performance, as well as the observed interindividual variability in AFT shoe responses and the factors proposed to mediate this variability. AFT shoes have been designed to improve RE and include thick lightweight resilient and compliant foams, stiff elements embedded in the foam, and curved shoe geometry. Research has explored how these components may contribute to RE improvements and has proposed various factors that may explain the interindividual variability, such as running speed, training level, sex, leg length, body mass, shoe size, and plantarflexion muscle-tendon unit properties. Comparing the characteristics of responders to non-responders and exploring relationships between these characteristics and RE responses can assist in identifying runners more likely to benefit from running in AFT.
Chapter Two presents an experimental study using a cross-sectional, repeated-measures design.  A heterogenous sample of sixty-four participants (32 males, 32 females) of varying running levels, experience, age, and anthropometric characteristics completed two laboratory sessions between two and seven days apart. The first included baseline information and participant characteristics for anthropometric, neuromuscular measures, and maximal oxygen uptake. The second session served as the experimental phase, during which RE variables were evaluated in the two different shoe conditions: Salomon S/Lab Phantasm 2 (AFT) and Salomon Aero Glide 2 (CONTROL). RE was measured over four 6-minute trials in an AFT and a CONTROL shoe, allocated in a randomised, crossover order. Descriptive statistics (means ± SD), inferential comparisons (paired samples t-tests, Chi square, and Fishers exact), and Pearson’s correlation coefficients were calculated to compare between responders and non-responders to AFT shoes and explain AFT shoe response. The mean improvement in RE (expressed in terms of oxygen consumption) was 4.13 ± 1.6% when wearing AFT compared to CONTROL shoes, with individual responses ranging from -2.62% to 11.01%. From all the variables collected, only gastrocnemius medialis (GM) stiffness normalised to leg length was significantly different (p = 0.046) between groups, with responders exhibiting greater GM stiffness (329.8 ± 36.6 N/m²) compared to non-responders (296.4 ± 47.3 N/m²). No other between-group differences were statistically significant. Two variables were significantly and moderately correlated to RE response, where greater navicular drop (r = 0.31, p = 0.012) and greater GM stiffness (normalised to leg length) (r = 0.35, p = 0.005) were linked to greater RE benefits from running in AFT shoes. Additionally greater gear ratio (r = 0.26, p = 0.040) and lower standing plantarflexion isometric strength (normalised to body weight) (r = -0.26, p = 0.041) displayed significant and small correlations with improvements in RE when running in AFT shoes. A multiple linear regression including standing plantarflexion isometric strength, navicular drop, gear ratio, and GM stiffness (normalised to leg length) explained 27% of the variance in our AFT RE responses (R² = 0.2731, adjusted R² = 0.223), with GM stiffness being the most important factor (B = 0.014, p = 0.015). 
Lastly, Chapter Three summarises the findings, strengths, limitations, and recommendations for future research. This research provides further insight into interindividual variability in RE responses to AFT, showing not all runners benefit equally from AFT shoes. Therefore, runners should be aware that they may not improve their RE via AFT, however, individuals with greater GM stiffness, navicular drop, and static ankle gear ratio, and with lower standing plantarflexion isometric strength may benefit to a greater extent from AFT shoe wear. These factors may help guide more personalised footwear selection and prescription. Future research should investigate whether training interventions that modify these characteristics can enhance responses to AFT footwear and examine how other biomechanical variables, such as foot strike patterns or flight times, may interact with RE responses.

year: 2025

title: From ecology to the assessment of multiple ecosystem services; a case study of estuarine bivalves

authors: Rullens, Vera

abstract: Estuarine and coastal environments provide a wide range of societal goods and services that need to be strategically managed to ensure sustainable use of resources. Ecosystem service (ES) assessments are transitioning from individual ES to multi-service assessments that consider interactions and grouping of ES (i.e. bundles). This thesis investigates the use of ecological mechanism (i.e. the links between ecological processes, functions, and ES) to derive insights into the associations between multiple ES provided by marine bivalves and the implications for management. In data-scarce marine environments, conventional spatial methods for assessing ES interactions and bundles are not always feasible. However, advancements can be made by focussing on ecological mechanisms, as for bivalves their ecological role has been extensively studied. The complex links between processes, functions, and ES were identified for bivalves, which were used to derive four ES bundles based on shared underpinning mechanisms. This study provides detailed descriptions of the specific (set of) ecological mechanisms per bundle, thereby gaining insights in how the ES are formed, the interactions between ES (synergies and trade-offs) and the environmental stressors they are prone to. Quantification of ES remains challenging, and measuring them in functionally similar species in different habitats is rarely considered, although ecological studies indicate differences are likely. I measured in situ bivalve contribution to water quality regulation for two functionally similar bivalve species (infaunal suspension-feeders) that dominate different estuarine habitats (subtidal and intertidal). Benthic chambers were used to measure solute fluxes (oxygen and nitrogen) and bed clearance rates as proxies for ES. Empirical findings indicated higher hourly productivity, nitrogen recycling, and water column filtration in the intertidal. However, when converted to daily ES estimates these patterns did not persist, emphasising the unequal contribution to functions and ES by functionally similar species and the non-linear scaling between them. Many ecological processes and functions are density dependent, hence spatial information on the distribution and density of bivalves is an important prerequisite to estimate ES. Probability of occurrence and density were predicted using Species Distribution Models (SDMs) for two estuarine bivalve species. Fine scale (100 m resolution) predictions showed different spatial patterns depending on habitat association. Species with a narrow distribution displayed good congruence between occurrence and density predictions, whereas species with a wide distribution demonstrated that a high probability of occurrence does not always equate to high density. Simultaneously considering both occurrence and density will improve decision-making and identify areas of greatest ecological value to the species of interest. Ecological mechanisms can be further applied to advance spatial predictions of multiple ES in marine environments, through process-based models that incorporate ecological principles to derive ES potential and assess natural variability in ES. Four ES (food provision, water quality regulation, nitrogen removal, and sediment stabilisation) were spatially predicted for two bivalve species. Spatial patterns in ES related to the species habitat association, with varying quantities and were driven by environmental conditions. Hotspot analyses on combined ES maps per species identified high-density areas for the provision of multiple ES simultaneously. These models provide a versatile tool to inform current management practices and can be further applied to test management scenarios. Collectively the results from this thesis demonstrated the utility and effectiveness of ecological mechanisms to determine ES interactions and bundles, and the spatial heterogeneity observed across estuaries. It also highlighted the interconnectedness of marine ES and the implications for their management.

text: From ecology to the assessment of multiple ecosystem services; a case study of estuarine bivalves Estuarine and coastal environments provide a wide range of societal goods and services that need to be strategically managed to ensure sustainable use of resources. Ecosystem service (ES) assessments are transitioning from individual ES to multi-service assessments that consider interactions and grouping of ES (i.e. bundles). This thesis investigates the use of ecological mechanism (i.e. the links between ecological processes, functions, and ES) to derive insights into the associations between multiple ES provided by marine bivalves and the implications for management. In data-scarce marine environments, conventional spatial methods for assessing ES interactions and bundles are not always feasible. However, advancements can be made by focussing on ecological mechanisms, as for bivalves their ecological role has been extensively studied. The complex links between processes, functions, and ES were identified for bivalves, which were used to derive four ES bundles based on shared underpinning mechanisms. This study provides detailed descriptions of the specific (set of) ecological mechanisms per bundle, thereby gaining insights in how the ES are formed, the interactions between ES (synergies and trade-offs) and the environmental stressors they are prone to. Quantification of ES remains challenging, and measuring them in functionally similar species in different habitats is rarely considered, although ecological studies indicate differences are likely. I measured in situ bivalve contribution to water quality regulation for two functionally similar bivalve species (infaunal suspension-feeders) that dominate different estuarine habitats (subtidal and intertidal). Benthic chambers were used to measure solute fluxes (oxygen and nitrogen) and bed clearance rates as proxies for ES. Empirical findings indicated higher hourly productivity, nitrogen recycling, and water column filtration in the intertidal. However, when converted to daily ES estimates these patterns did not persist, emphasising the unequal contribution to functions and ES by functionally similar species and the non-linear scaling between them. Many ecological processes and functions are density dependent, hence spatial information on the distribution and density of bivalves is an important prerequisite to estimate ES. Probability of occurrence and density were predicted using Species Distribution Models (SDMs) for two estuarine bivalve species. Fine scale (100 m resolution) predictions showed different spatial patterns depending on habitat association. Species with a narrow distribution displayed good congruence between occurrence and density predictions, whereas species with a wide distribution demonstrated that a high probability of occurrence does not always equate to high density. Simultaneously considering both occurrence and density will improve decision-making and identify areas of greatest ecological value to the species of interest. Ecological mechanisms can be further applied to advance spatial predictions of multiple ES in marine environments, through process-based models that incorporate ecological principles to derive ES potential and assess natural variability in ES. Four ES (food provision, water quality regulation, nitrogen removal, and sediment stabilisation) were spatially predicted for two bivalve species. Spatial patterns in ES related to the species habitat association, with varying quantities and were driven by environmental conditions. Hotspot analyses on combined ES maps per species identified high-density areas for the provision of multiple ES simultaneously. These models provide a versatile tool to inform current management practices and can be further applied to test management scenarios. Collectively the results from this thesis demonstrated the utility and effectiveness of ecological mechanisms to determine ES interactions and bundles, and the spatial heterogeneity observed across estuaries. It also highlighted the interconnectedness of marine ES and the implications for their management.

year: 2021

title: The Unmet Legal, Social and Cultural Needs of Māori with Disabilities

authors: Hickey, Susan Jane

subjects: Māori

abstract: There is little work done in the area of indigenous disability identity issues and how they are recognised in domestic and international human rights laws. The discourse of disability has always been based on social constructionism and without it, there is no identity. I discuss its relevance to indigenous (Māori) with disabilities and how the multiplicitous nature of the identity of  other  has a particular impact when indigenous, gender and disability are all identified from marginalised groups. I also explore the impact of westernised thinking around impairment, in particular the models of disabilities on indigenous well-being. The issues of family (whānau), whakawhanaungatanga (family relationships), interdependence (community) and collectivity identities central to indigenous thinking are largely ignored by law and policy, yet central to indigenous identity. This ignorance in policy has led to the disparities that continue to remain for indigenous persons with disabilities, particularly those from within thematic identity groups.

text: The Unmet Legal, Social and Cultural Needs of Māori with Disabilities There is little work done in the area of indigenous disability identity issues and how they are recognised in domestic and international human rights laws. The discourse of disability has always been based on social constructionism and without it, there is no identity. I discuss its relevance to indigenous (Māori) with disabilities and how the multiplicitous nature of the identity of  other  has a particular impact when indigenous, gender and disability are all identified from marginalised groups. I also explore the impact of westernised thinking around impairment, in particular the models of disabilities on indigenous well-being. The issues of family (whānau), whakawhanaungatanga (family relationships), interdependence (community) and collectivity identities central to indigenous thinking are largely ignored by law and policy, yet central to indigenous identity. This ignorance in policy has led to the disparities that continue to remain for indigenous persons with disabilities, particularly those from within thematic identity groups.

year: 2008