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leg muscles used for propulsion in the leg-push skating for normal-push stroking, also for double-push stroking, and also upper body moves for skating with no poling.

- - Why this list matters
- - Priorities among the muscles
- - Complexity of skating
- - Comparison with other motions (classic striding, bicycling)

see also

  

[ under construction ] 

 

Introduction

These are muscles used to do actual physical work for forward propulsion: not just position bones and joints so that other muscles can do propulsion work.

This list is mainly for skating with no poles, using normal-push leg technique.

Additional muscles are employed in the "double-push" leg technique used much by inline speedskating racers.

This list of muscle moves is not the "right" way to skate. Rather it offers a set of options. Few skaters use all these muscle moves, and I doubt there is any skater who uses all of them all the time.

The main purpose of this analysis is to expose skaters and skate instructors to more choices -- more variety and more freedom. It's up to each skater and coach to work out which subset of these is best for them in each situation, and in what "proportion" to emphasize each move in their chosen subset.

A key puzzle of learning skating technique is how to manage the complexity of these possibilities. A gifted instructor helps each learning skater find simplifications that are appropriate for their current needs and goals.

Why this list matters

Finding another set of muscles to use is like getting a bigger car engine. The main body-performance "bottleneck" for most skaters is in build-up in the main big leg muscles of chemical by-products from intense production of work. So spreading the load to other less-obvious muscles allows the main big muscles to work easier and longer.

Why doesn't our body learn to use all these muscles automatically?

Unlike walking or running, skating is not a natural movement pattern for humans. So we need help in discovering and developing and then remembering how to use many of the muscle moves:

  • Our unconscious neuro-muscular control centers need help in discovering which other muscles can be effective for skating.

  • How to use -- our neuro-muscular centers also need help to learn how each muscle can be effective, since angle configuration and timing matters.

  • Forget -- Even if we learned all the muscle moves once, when we focus on one or two, we forget one of the others.

Perhaps our neuro-muscular control centers do not have enough "computer power" to handle coordinating so many muscles at once -- since the normal propulsion movements of walking and running use fewer muscles.

  • Save energy -- Often our neuro-muscular control center is usually trying to save energy -- so it lowers the usage of most "non-obvious" muscles unless we consciously remind it.

  • Minimize muscle mass -- I suspect that our neuro-muscular control center is "programmed" to try to re-use the same obvious big muscles for many different tasks, instead of recruiting other muscles used at a high power-level only for one task (e.g. skating).

Because using other muscles at a higher power-level will increase their muscle mass, and extra muscle mass had some bad costs in the old evolutionary survival-reproduction game: (a) higher basal metabolism; (b) more body weight to be carried around; (c) lower calories-per-kg of stored energy. So it takes conscious effort for us nowadays, for our own modern purposes, to overcome this instinct.

  • Develop -- Each specific muscles needs to have its endurance and speed and strength developed through appropriate training exercises, in order to make its best contribution to total propulsion power.

If we don't know all the specific muscles and their moves, then we don't know how to best train the specific muscles. Not that each muscle needs its own special exercise, but need to think about where it gets stimulated in an overall program of training. The default is simplest: just remember to use that muscle sometimes in normal fun skating.

Priorities for better utilization

The hip extension move [ see more below ] likely does the highest proportion of propulsive work, but almost nobody neglects to use or train them, since they're used in our natural motions of walking and running (and bicycling).

Here's some likely opportunities for improvement:

  • knee extension in Phase 3 [ see more below ] -- Major leg muscle but often neglected, because it's full utilization for skating requires the non-intuitive move of pushing directly out to the side -- which then often feels like the lower leg is slicing forward, very strange to our walking instincts which want to be feeling the leg pushing backward.

  • ankle flexion in Phase 1b [ see more below ] -- Many people flex their ankles some in skating, but not strongly for effective propulsion. And flexing the ankles has another benefit in configuring the leg joints for bigger use of the knee extension muscles in Phase 3 and Phase 2.

  • ankle supination in Phase 3 [ see more below ] -- Pushing with the ankle pronated feels like it's good because it's "aiming" further out toward the side. This can be useful in Phase 1, but it also shortens the leg -- so it needs to be un-done for full extension at the end of the stroke in Phase 3. The ankle supination move brings the ankle into the hip-heel-toe plane for full leg extension.

  • hip abduction in Phase 1 [ see more below ]. Many people think that Phase 1 is a "passive glide" phase. But actually it's a straightforward opportunity to start pushing propulsively on the skate or ski -- or at least to support the final phase of the previous leg's push.

other notes on usage

  • ankle extension in Phase 3b [ see more below ]. This makes a valuable contribution close to ground-contact, and not many people forget the toe-push move, because it's natural from running. Except that inline-skaters and non-klap-ice-skaters sometimes forget the toe-push when they try ski-skating, because it's not possible in the other skating motion they practice more hours for more months of the year.

  • ankle pronation in Phase 1 [ see more below ] -- makes its contribution close to ground-contact (which is good) -- but it's tricky to learn to apply muscular force to it (instead of just collapsing) and also still remember to use the ankle-supination in for full extension in Phase 3.

Complexity of skating

12 distinct muscle moves (see below), each with its own distinct functional role, is a lot -- and that's only in the hips + legs.

There's also 5-7 more muscles with distinct roles in the upper body for skating with no poles (see below). 

For a total of 17-19 propulsive muscle moves for skating with no poles.

Compare with other motions

  • Classic striding leg-push with no poles in cross-country skiing has only 4 muscles used for actual propulsion: ankle-extension, knee-flexion, hip-flexion, and pelvis-rotation. Plus one propulsive role in the abdomen and back (back-extension to apply reactive down-force thru the leg), and one or two more (depends on how you count) in the arms and shoulders (for arm-swing to apply reactive forward-force) -- for a total of 6-7 propulsive muscles for classic striding on skis with no poles.

  • Running has the same as Classic striding in cross-country skiing.

  • Bicycling has 6 in the hips + legs: ankle-flexion, ankle-extension, knee-flexion, knee-extension, hip-flexion, hip-extension. Also some pelvis-rocker muscles, though maybe they are effectively while standing. Also when standing can help pull with the arms. Total of 6-8 propulsive muscle functions.

Poling included in comparison

Double-poling while skating adds more muscle functions: one or two for abdominal crunch (if define separate upper and lower abdomen-flexion), three or four for arm-push (drive-down-and-back thru shoulder, elbow-extension, internal-shoulder-rotation, and perhaps muscles to drive down through thru wrist), and back-extension to build potential energy which can drive the next pole-push, for a total of 5-7 muscles.

  • V1 skate (a.k.a. "offset", "paddle-dance"): In offset poling for V1 skate, there is also shoulder rotation to drive down the poling-side pole. Also two more muscle roles acting thru the shoulder generates reactive side-force from an extra inward-outward pole-arm-recovery move on the pole-recovery side. But subtract arm-swing and back-extension for reactive down-force, since those are now used in poling. Adds 8-10 muscle roles, less 3, for a net increase of 5-7 distinct propulsive muscle roles, for a net total of 20-24 propulsive muscles for V1.

  • V2 skate (a.k.a. "1-skate", "double-dance"): instead of the shoulder-rotation of V1 offset poling, V2 poling adds knee-flexion work to help drive the poles down and back into the snow, for a net total of 18-22 propulsive muscles for V2.

Classic skiing motions with poling included:

  • Classic striding (a.k.a. "kick-and-glide", "diagonal stride") with poling adds more muscle functions: one or two for abdominal crunch (if define separate upper-abdomen-flexion and lower abdomen-hip-flexion), three or four for arm-push (drive-down-and-back thru shoulder, elbow-extension, internal-shoulder-rotation, and perhaps muscles to drive down through thru wrist), and also uses back-extension in another propulsive role: to add potential energy of raising the torso+shoulders+head, which can be applied to the next pole-push. And perhaps not lose the one or two for the foward arm-swing which generates reactive forward-force. Net total of 10-13 muscles in propulsive roles.

  • Double-poling (pure poling with no leg-push): 5 propulsive muscle roles in the legs and hips: ankle-extension, knee-flexion, knee-extension, hip-flexion (in crunching down), hip-extension (in raising torso to add potential energy), plus 5-6 in upper body and arms: three or four for arm-push (drive-down-and-back thru shoulder, elbow-extension, internal-shoulder-rotation, and perhaps muscles to drive down through thru wrist), abdomen-flexion, and back-extension to add potential energy of raising the torso+shoulders+head. Total of 10-11 muscles in propulsive roles.

Leg + Hip muscle moves

These muscle moves are available to add forward propulsion power in skating:

(this move is often associated with the "shin" muscle)

(this move is often associated with the "calf" muscle)

Often thought of as an error, pronation can also effective for propulsion provided that the starting configuration of the leg joints and the timing are right.

  • ankle supination [ more info ] -- most effective in Phase 3 (provided that the ankle was earlier pronated in Phase 1b or Phase 2).

By accelerating the mass of the lower leg to move faster (and further) inward toward the other side during the middle of Phase R, the knee flexion move (or hip-leg-rotation move) adds kinetic energy, which is then transmitted to the snow thru the other foot when the lower leg's side-motion is stopped in the last part of Phase R (and then is sent back outward toward set-down in Phase 0). The more quickly and strongly the lower leg is moved inward, the more kinetic energy can go into the other foot by reactive side-force.

(knee-flexion is often associated with the "hamstring" muscle)

(this move is often associated with the "quadriceps" muscles)

Perhaps more accurate kinesiology to call this move medial hip rotation.

Perhaps more accurate kinesiology to call this move lateral hip rotation.

(this move is often associated with the "gluteus maximus" muscle)

In Phases R + 0, the hip abduction move does reactive-force work on the previous leg-push stroke by the other leg, by decelerating and stopping the recovering leg's inward motion in Phase R, then starting and accelerating the mass of the leg outward in Phase 0.

[ inline: Inline-skaters using a "double-push" leg stroke could possibly also use the "hip adduction" muscles in a similar way for propulsion in the first inward push. ]

By accelerating the mass of the entire recovering leg to move faster (and further) inward toward the other side during the early and middle parts of Phase R, the hip adduction move adds kinetic energy, which is then transmitted to the snow thru the other foot when the entire lower leg's side-motion is stopped in the last part of Phase R (and then is sent back outward toward set-down in Phase 0). The more quickly and strongly the leg is moved inward, the more kinetic energy can go into the other foot by reactive side-force.

Perhaps more accurate kinesiology to call this move lumbar spinal rotation.

Double-push / in-push leg+hip muscles

Double-push already includes all the muscle moves used in phases 1, 2, 3 of normal-push skating (see above).

Here are the additional leg and hip muscle moves used propulsively in phases U0, U1, and U3:

Perhaps more accurate kinesiology to call this move lateral hip rotation.

Perhaps more accurate kinesiology to call this move lumbar spinal rotation.

Upper Body muscles in No-Poles skating

There's 5-7 more muscles with propulsive roles in the upper body, even when no poles are being used.

  • back-extension -- the move of stopping the falling and then raising the mass of upper body applies beneficial reactive down-force thru the leg, mainly in Phase 3.

This gets tricky because there is also anti-beneficial reactive up-force thru the leg, mainly during Phase 1. So timing is critical: the mass of the upper body should be dropping at the start of Phase 2, then get slowed and stopped during the finish of Phase 2 and start of Phase 3, then started and accelerated upward during Phase 3. It should reach its high point somewhere during Phase 0 or 1.

The point of this timing is that the down-force comes when the vector of the line of the leg relative to the ground surface has the smallest vertical component and the largest sideways and backward component, so more of the reactive down-force gets converted into additional forward-propulsion. The up-force comes when the vector of the leg relative to the ground has the largest vertical component, so more of the reactive up-force goes into "lightening" the impact into the ground, and less into softening the propulsion force. The result is a net positive for forward propulsion work.

  • abdomen-torso side-swing move for reactive side-force -- in Phase 1 and again in Phase 3.

In phase 1 it "catches" the kinetic energy from the side-weight-shift of the previous leg-push and by decelerating the mass of the upper body, generates beneficial reactive side-force to the current push.

In Phase 3, it starts the side-weight-shift of the upper body toward the other side, and this acceleration generates beneficial reactive-side-force to the current push. The stronger and quicker the acceleration of the upper body, the more work added to propulsion.

Note that this rotation or swing is in the opposite direction of the rotation of the pelvis and hips in the forward-hip-rotation move.

  • chest-shoulder side-swing move for reactive side force (perhaps distinct from the lower abdoment-torso move) -- in Phase 1 and again in Phase 3.

Same reactive-force acceleration / deceleration timing considerations as for the abdomen-torso side-swing move.

  • side-swing of entire arm inward from shoulder, and
  • side-swing of entire arm outward from shoulder -- in Phase 1 and again in Phase 3.

Similar reactive-force acceleration / deceleration timing considerations as for the abdomen-torso side-swing move.

Actually this is two distinct muscle moves, one for each arm -- since the swing direction is inward for one arm and outward for the other, each using different muscles.

  • side-swing of forearm inward from elbow joint, and
  • side-swing of forearm from elbow joint in outward direction (perhaps distinct from side-swing of entire arm from shoulder) -- in Phase 1 and again in Phase 3.

Similar reactive-force acceleration / deceleration timing considerations as for the abdomen-torso side-swing move.

Actually this is two distinct muscle moves, one for each forearm -- since the swing direction is inward for one arm and outward for the other, each using different muscles.

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