For one of my classes, I had to write a piece on the biomechanics and physiological requirements for an effective skating stride. It is full of technical jargon, but if you’re interested in what I think about the skating stride, give it a read! Post any questions for clarification in the comments section.
Ice hockey skating is very technical and the degree of biomechanical efficiency is important for speed and acceleration. The two most important variables affecting skating speed are stride length and stride frequency. There are three phases of the skating stride: the support phase, the push phase, and the recovery phase. Having an understanding of the physiological varaibles that contribute to the effectiveness of the three skating phases and how they work together to affect stride length and stride frequency is essential when training a hockey player.
During the skating stride, there is a point where the body’s weight is supported by one leg while the other leg applies force to the ice to propel the skater forward. This is called the support phase. Uni-lateral leg strength is essential for this phase of the stride. When a skater has excellent uni-lateral leg strength, they have two advantages. One, is that they are able to maintain a lower knee bend (shown by increased hip and knee flexion) while skating. This permits the skater to decrease the angle between the pushing leg and the ice when striding out. It follows that the skater will be able to exert more horizontal and lateral rather than vertical force into the ice when he or she has an increased capability to maintain knee bend. A lower knee bend, and therefore a smaller angle between the push leg and the ice at extension also permits the skate blade to keep in contact with the ice during the push phase. Since Power = Work / Time, we can ostensibly improve the amount of work that a skater can do given that their capability to generate power is held constant if we increase the amount of blade contact time with the ice that it is propelling the skater forward.
To improve the uni-lateral leg strength with the goal of improving skating performance, we need pay attention to uni-lateral leg force production, but also alignment and recruitment patterns. An athlete looking to improve uni-lateral leg strength must have the ability to stabilize the core while on one leg. He must also be able to maintain alignment of the knee and foot while in a deep squat. A common “energy leakage” which manifests in hockey players is gluteal amnesia. This can lead to valgus knee alignment and pronation of the foot. This occurs because the gluteus maximus, which is the main hip extensor, is also a powerful external rotator of the femur. If it is not firing properly, the hamstring group will take over in the duties of extending the hips, but they will not be able to stabilize the leg. Also, if the gluteus maximus is not firing properly, when an athlete seeks to get low in a single leg squat position, his pelvic will rotate posteriorly, thus placing unnatural stress on the lumbar spine. So, in order to train uni-lateral leg strength, the athlete must be able to recruit the gluteus maximus and maintain neutral pelvic posture before increasing the intensity of their lifts (the amount of force produced during each lift).
Improving the support phase mechanics is most important for improving a skater’s stride length. Improving stride frequency is a function of the push phase. An effective push phase relies again on mechanical and force production characteristics. The same alignment and gluteus maximus recruitment factors as discussed in the support phase are necessary for optimal efficiency during leg extension in the push phase. Foot pronation or valgus knee alignment would lead to an energy leakage while the leg strides out. However, the important force production characteristic during the push phase is peak power. Again, using the relationship of Power = Linear Displacement / Time (replacing Work with Linear Displacement), this time holding Linear Displacement constant, the more power that the legs can generate, now, the less Time the blade will be in contact with the ice. This has the function of increasing the stride rate.
An effective recovery phase requires hip flexors and adductors that can withstand rapid stretch and contraction. The recovery of the leg from extension back to the support phase is not the limiting factor in skating speed (the push phase takes longer and requires more force productive resources), so the eccentric-concentric coupling capabilities for the hip flexors and adductors do not need to be trained. Rather, their ability to constantly withstand eccentric forces at high velocities must be trained in order to reduce the risk of injuries. The first factor that must be ensured is active range of motion of the hip flexors and adductors. The second is the eccentric strength of the hip flexors and adductors at the end their active range motion.