Conventional walking and walking uphill

The aim of the present study was to assess differences in muscle activation and physiological responses between NW and W in horizontal and uphill walking conditions. 

Nine expert Nordic Walkers performed 5-minute W and NW trials on a treadmill at 4 km / h on 0% and 15% inclines. Electromyographic activity of seven upper body muscles and five leg muscles were recorded, as well as oxygen consumption and pole strength during NW was measured. 

VO2 during NW was 22.3% higher at 0% and only 6.9% higher at 15% than during W, while upper body muscle activation was 2- to 15-fold higher in both conditions. Lower body muscle activation was similarly increased during NW and W in the uphill conditions, while the increase in spinal erector muscle activity was less during NW than W. The lack of a significant increase in pole strength during uphill walking may explain the lower additional energy expenditure of NW, indicating less activation of upper body muscles to lift the body against gravity. NW seemed to reduce lower back muscle contraction in uphill conditions, suggesting that pole walking may reduce the effort to control trunk oscillations and may contribute to work production during NW.