Fatigue and perceived comfort of occupational footwear

The participants will be required to stand on both feet within a confined area of 900 mm / 600 m at a work bench for 4 h. During each 1-hour period the participants will perform three other activities intermittently (every 10-min) as part of the intervention (See below for intervention activities). At the end of each 1-hour interval a test battery will be conduced assessing muscle activity (EMG) during standing, perceived boot comfort, walk gait, balance, muscle stiffness, plantar flexor force production and muscle function (excitation-contraction coupling efficiency). The intervention activities consist: Standing – stand on two feet within 900 m / 600 mm area whilst completing non-physical work such as watching movies on computer/tablet, surfing the internet or studying. 1-min step-ups – 1 min of step ups at frequency of 88 bpm onto 40 cm box using alternate legs to step up and then down (i.e. simulate stair walking and other tasks requiring leg work). 6 x lift load from floor – lift load (2 x 5-kg dumbbells for men and 2 x 2.5-kg dumbbells for women) from floor using safe lifting technique to a standing position then replace load on floor at a rate of one lift-and-replace every 5 s (total time = 30 s). 300 m walk – walk at self-selected speed for 300 m; speed during first walk will be recorded and repeated for each individual on every walk occasion. Participants will drink 300 ml of water in each of the first and second 2-hour periods of the intervention, and a standard, small meal will be given after the completion of the test battery performed at the 2-hour mark of the intervention. Each participant will partake in three testing sessions each separated by a minimum of 72 h. In each individual session a different pair of steel cap work boots will be worn. Either the Steel Blue Argyle (model 312102), Steel Blue Southern Cross Zip (312661) or Blacksmith Sparky (804-80733). All sessions will be conducted by an experienced sport science researcher with 4 years experience.