Current winter footwear provides inadequate protection from slip-related injuries on ice, and there is limited research investigating the optimal design of anti-slip devices. This study examined how ice cleat spike height and position in the heel affect slipping. No differences could be observed between spike conditions, but results demonstrated that heel spikes may prevent slips initiated between heel contact and foot-flat and forefoot spikes may be necessary to prevent foot-flat slips. Further analysis compared slip outcomes measured using two slip onset definitions: 1) heel contact, and 2) the first point of increasing positive heel acceleration. Slip onset defined as time of heel contact overestimated the number of slips and slip distances. These results demonstrate that ice cleats have the potential to protect pedestrians from slipping but some styles available to consumers (i.e. heel spikes only) may not be adequate. Choice of slip definition in footwear evaluations can significantly influence study outcomes.

Current winter footwear provides inadequate protection from slip-related injuries on ice, and there is limited research investigating the optimal design of anti-slip devices. This study examined how ice cleat spike height and position in the heel affect slipping. No differences could be observed between spike conditions, but results demonstrated that heel spikes may prevent slips initiated between heel contact and foot-flat and forefoot spikes may be necessary to prevent foot-flat slips. Further analysis compared slip outcomes measured using two slip onset definitions: 1) heel contact, and 2) the first point of increasing positive heel acceleration. Slip onset defined as time of heel contact overestimated the number of slips and slip distances. These results demonstrate that ice cleats have the potential to protect pedestrians from slipping but some styles available to consumers (i.e. heel spikes only) may not be adequate. Choice of slip definition in footwear evaluations can significantly influence study outcomes.

Winter conditions, characterized by snow and lowered temperatures, can make travel by foot difficult. Older adults aged 65 and above are especially at risk of slipping and falling on icy or snowy surfaces. Minor falls can result in severe injuries due to their frailty. Traditional methods of reducing this risk, like plowing or using sand and salt, may not always be effective preventive measures. Several municipalities in Sweden have taken action to combat this issue and introduced subsidized ice cleat distribution programs for older adults. It is unclear how these programs are designed and whether they are effective in promoting the use of ice cleats. This thesis uses a mixed-method approach drawing on data collected from multiple sources to analyze and evaluate the programs. Paper I presents a program theory model, outlining the essential components required for implementing a program and describing the causal connections from the program's introduction and necessary conditions to its anticipated impact. Survey data from intervention municipalities suggest that about 40% of the target group participated by retrieving a pair of devices, and 90% of all ice cleats were eventually distributed. Paper II presents an outcome evaluation suggesting that individuals exposed to a distribution program increase ice cleat use. Analyses of the self-reported data on ice cleat use show an increase of 7.5 percentage points. Estimations suggest that general use could be 17.3% if one pair of cleats were distributed to all eligible citizens. Future research is needed to investigate the programs' effect on fall-related injuries on ice and snow. In addition, in-depth interviews with program policymakers should be considered to provide further insights into the design and implementation of these programs. / Vinterförhållanden, som kännetecknas av snö och låga temperaturer, kan göra det svårt att resa till fots. Äldre vuxna, i åldern 65 och äldre, löper större risk att halka och falla på isiga eller snöiga ytor, där även mindre fall kan leda till allvarliga skador på grund av deras sårbarhet. Traditionella metoder för att minska denna risk, som snöplogning eller spridning av sand och salt, kanske inte är tillräckligt effektiva. Flera kommuner i Sverige har vidtagit åtgärder för att bekämpa detta problem och infört subventionerade program som delar ut broddar till den äldre befolkningen. Det är oklart hur dessa program är utformade och om de är effektiva när det gäller att främja användningen av broddar. Denna avhandling använder en blandad metod som bygger på data som samlats in från flera källor för att analysera och utvärdera programmen. I Paper I presenteras en programteoretisk modell som beskriver de väsentliga komponenter som krävs för att implementera ett program och beskriver orsakssambanden från programmets introduktion och nödvändiga förutsättningar till dess förväntade effekt. Undersökningsdata från interventionskommuner tyder på att cirka 40 % av målgruppen deltog i programmen genom att hämta upp ett par broddar, och 90 % av alla halkskydd distribuerades. Effektutvärderingen som presenteras i Paper II tyder på att exponering för ett distributionsprogram ökar användningen av broddar. Självrapporterade data om användning av halkskydden tyder på en ökning med 7,5 procentenheter, och ytterligare skattningar visar att den totala användningen kan bli 17,3% om ett par broddar distribuerades till alla berättigade medborgare. Framtida forskning behövs för att undersöka programmens effekt på fallrelaterade skador på is och snö. Dessutom bör djupintervjuer med programpolitiska beslutsfattare övervägas för att ge ytterligare insikter om utformningen och genomförandet av dessa program. / Several Swedish municipalities have introduced subsidized ice cleat distribution programs to combat the risk of fall-related injuries on icy or snowy surfaces, especially among older adults aged 65 and above. Using a mixed-method approach and data collected from multiple sources, the thesis evaluates the effectiveness of these programs. The thesis presents a program theory model outlining the components required for implementing a program and its anticipated impact. Survey data from intervention municipalities show that 40% of the target group participated in the programs by retrieving a pair of devices, and 90% of all ice cleats were distributed. The outcome evaluation suggests that exposure to a distribution program increases ice cleat use by 7.5 percentage points. If one pair of cleats were distributed to all eligible citizens, about 17.3% would use the devices. The thesis calls for future research to investigate the programs' effect on fall-related injuries and suggests in-depth interviews with program policymakers to provide further insights into the design and implementation of these programs.