To me, the foot is one of the more important lower body areas that often can be a cause of dysfunction. Because the foot is typically the only body part interacting with the ground, if the foot isn’t function optimally, the same will occur up the kinetic chain. The foot has 2 main functions:
A rigid lever for propulsion
The foot actually acts as a lever when we are walking and running. During push off, the foot will fold inwards (think of it similar to ballerina stance) to create stiffness and the body to move forward. By having the foot stiffen, it allows the ankle to plantarflex in a closed chain to propel the weight of our body over our foot. This is what allows us to walk and run so efficiently. So, in order to plantarflex your ankle, your foot needs to fold and become stiff.
A mobile adapter to the ground
Contrary to being a rigid lever, the foot also acts as a mobile adapter. This means that the foot will adapt to the ground by “fanning” or spreading out. This allows us to walk on rough terrain effectively by adapting to the environment. The foot’s ability to fan is also important in accepting our body weight when we walk and run, and dissipate the forces applied on the foot to reduce the stress of doing so. The foot needs to fan when the ankle is dorsiflexing in weightbearing.
However, the foot may perform differently in skates than while walking or running, although the same functional principles of rigid lever and mobile adapter apply.
Foot mechanics in skating
In hockey research, the foot is definitely one of the more challenging areas to study because it sits inside a stiff and rigid skate. However, there have been some interesting findings when looking at the foot and ankle during ice hockey skating using pressure mapping.
Because skating is different than walking and running, the foot mechanics will be different. To begin with, in order to move in hockey, we have to overcome the frictionless surface of the ice. A hockey start consists of turning the leg to grip the skate blade into the ice and push the body forward, similar to running like running.
The Foot as a Mobile Adapter
Lafontaine et al. studied the knee and ankle during a skating start. They identified that skaters utilize some degree of tibial abduction and external rotation as well as ankle abduction, eversion and dorsiflexion during forward skating. Dewan et al. also determined that the ankle is near maximum eversion at the time of push off. A lot of these movements will create a kinetic chain effect on the foot. Foot pronation often accompanies tibial abduction and external rotation. Foot pronation is also a conjunct movement when the foot abducts and everts in weightbearing, especially when approaching end range eversion. Therefore, during push off in a skating start, the foot must act as a mobile adapter to allow these movements to occur high up the chain. Dewan et al. also studied the foot in forward skating using pressure mapping inside the skate. They found that in the stance phase, there was an increase in pressure on the medial and lateral aspects of the skate, suggesting that the foot is “fanning” as mobile adapting foot would. This fanning also accompanies the greatest amount of dorsiflexion during the skating stride. So, if the foot can’t fan, dorsiflexion will be limited.
The Foot as a Rigid Lever
But just like walking and running, the foot must quickly transition to a rigid lever. Stidwill et al. concluded that because the ankle external rotates and everts in a stiff boot during stance, resulting forces applied into the medial and lateral aspects of the boot may increase eversion torque and may be returned to the ankle complex during push-off. This suggests that players may actually use the stiffness of the boot to lever the ankle during push-off. Again, this will have implications down the kinetic chain to the foot. If the foot is soft or acting as a mobile adapter during this phase of skating, the ankle will not have a solid base to lever from and will lose potential energy. Therefore, the foot must transition from a mobile adapter in stance, to allow for tibial and ankle motions, to a rigid lever during push-off to provide a stable base for the ankle to lever on the skate boot.
Stidwill, T. J., Turcotte, R. A., Dixon, P., & Pearsall, D. J. (2009). Force transducer system for measurement of ice hockey skating force. Sports Engineering, 12(2), 63-68.
How to optimize the foot for hockey players
Although the foot needs both stability and mobility inside the skate, wearing skates that much can cause the foot to get stiff, which can affect the foot mechanics during skating. In order to maximize mobility and strength, try these
Plantar fascia release
Big toe stretch
3 way knee to wall
Foot arching
References
Dewan, C., Pearsall, D., & Turcotte, R. (2004). Ankle kinematics during forward hockey skating: Acceleration to constant velocity. In ISBS-Conference Proceedings Archive
Dewan, C., Pearsall, D., & Turcotte, R. (2004). Dynamic pressure measurement about the foot and ankle. In ISBS-Conference Proceedings Archive.
Lafontaine, D. (2007). Three-dimensional kinematics of the knee and ankle joints for three consecutive push-offs during ice hockey skating starts. Sports Biomechanics, 6(3), 391-406.
Stidwill, T. J., Turcotte, R. A., Dixon, P., & Pearsall, D. J. (2009). Force transducer system for measurement of ice hockey skating force. Sports Engineering, 12(2), 63-68.