Performance footwear testing
Slip resistance and traction is extremely important in footwear designed for performance in more difficult terrain whether this is a cross-trainer, hiking or mountain boot, or a boot intended for military application. It is important that the sole is constructed to meet the challenges of a range of conditions. SATRA can assess slip resistance on a variety of specialist surfaces, for example frosted ice or concrete and metal grills across varying wet and dry temperatures.
Comfort plays a significant role in performance footwear where the wearer will have high expectations. Comfortable footwear enables the wearer to perform to his or her maximum limits and generates brand loyalty and encourages repeat sales. Although comfort is dependent on a complex range of factors and is highly subjective, SATRA provides a range of services to quantify the comfort of products and assess how specific materials and constructions enhance comfort.
A degree of stiffness may be beneficial in certain types of performance footwear, for example, in walking boots where extra support and protection are required. If footwear is too rigid, however, the support becomes counter-productive. SATRA is experienced in assessing footwear fitness for purpose based on the activity for which the footwear is intended.
Sole durability is critical in high performance footwear, therefore, testing needs to be able to mimic the forces normally experienced during wear. SATRA achieves this by placing footwear on a prosthetic foot that ‘walks’ on an abrasive surface mimicking the forces normally experienced during wear. Premature wear in mountain or military footwear could compromise both performance and safety so it is vital to identify any potential weakness long before the product sees active service.
Shock absorption and ground insulation
Although the human body can be very effective in absorbing shock when jumping, running or walking, injuries can still occur through impact loading to the foot. A number of health problems have been linked to one-off shock loading or repeated shock loading. These include lower back pain, joint disorders and heel bone fractures. At SATRA we can conduct repeatable mechanised tests to determine the shock capabilities of materials and whole footwear. As well as providing product verification and assurance that quality is consistent, such testing can make a valuable contribution to future product design. As well as general cushioning, footwear worn outdoors on rough ground should help to protect the wearer from feel-through to avoid under-foot discomfort or injury. SATRA’s ground insulation test assesses feel-through using pressure mapping techniques combined with a measurement of foot-side distortion when an object is pressed against the sole.
Most outdoor performance footwear worn in temperate or tropical climates needs to be water resistant for extended periods. Water resistance is not just a matter of keeping the wearer’s feet dry but also controlling the amount of water absorbed by the upper or other components of the footwear. Water absorption will make the footwear heavier and may affect the insulating properties or cause components such as insoles to break down. SATRA has a number of water resistance tests designed to assess this key property, including a dynamic water resistance tester and an abrasive water durability test.
If footwear is to be worn in extreme conditions where heat and cold can vary considerably it is important to keep the wearer’s feet as dry as possible for comfort and to maintain foot health. In cold environments the foot can feel even colder if thermal conductivity increases due to damp or wet conditions inside the footwear. SATRA is well-equipped to identify all moisture management challenges and opportunities and can carry out specialist testing in a variety of conditions to simulate a range of climates.
High thermal insulation performance is particularly important for the comfort and safety of wearers in cold conditions. Conversely, low insulation is desirable when trying to keep feet cool in hot environments. SATRA’s facilities provide everything required for a total assessment.
Performance footwear must fit correctly to aid foot comfort and help to minimise the risk of blisters or other injuries. As well as assisting companies in achieving consistent sizing, SATRA uses a variety of methods to help assess footwear fit and comfort.