Hip Extension End Range of Motion Strength Training

Disclaimer : This information is not guaranteed to be accurate and I am not liable if you make any decisions or take any actions, in terms of medical treatment, health decisions, exercise, behavior or anything else based on the information presented.  I am not telling you any decisions to make even if I use terms like "you" but am using the word "you" as part of a writing style to simplify writing.  Any suggestions for what "you" should do are not for you personally to do but what someone might do as part of a exercise or nutrition program which might help some people's health and make other people's health worse.  You should not do any activity that will make your health worse even if "you" should do it according to the program described.  If the information is wrong and you believe it is true, act on it and it causes you problems, I am not responsible because I have warned you the information is not guaranteed to be accurate.

This is not a exercise prescription for the reader but a exercise description.  I am not claiming the reader should do this exercise or that it is safe for the reader.  This is not medical advice.

This is for the right hip, for the left hip follow the instructions but switch the words right and left

This is for only strength training one hip at a time not both simultaneously

There is only one pelvis and two hips but the one pelvis has a right and a left side which I will call the right and left pelvis

Right Hip isometric hip extension against gravity while lying prone on your stomach

Surface

Use a surface that is soft enough to avoid causing swelling or inflamation through contact with the surface but hard enough to allow you to do the movement pattern described

The exercise

Raise the right knee by extending at the right hip

Although the instructions are written for the right side you will need to know both sides

Raise it as high as you can for your tolerable level of comfort without extending the lower back a practically significant amount

Initially isometrically hold it just long enough to choose the proper height for each side and not a second longer, this might take multiple practice tries

Once you figure out the appropriate height to hold the exercise at then time how long you can hold it on the side with less endurance for your tolerable level of comfort or the maximum time you can do without scheduling conflicts whichever amount of time is smaller

Do the side with greater endurance the same amount of time as the side with less endurance

Once you know which side has less endurance than do the side with less endurance first

You can alternate which side you do first until you know

This exercise should only be done isometrically and for short periods of time until you are familiar with it enough to know how not to accidentally extend your low back

Once you know this you can do it concentrically and eccentrically or isometrically and for longer periods of time

Instead of holding it for one long duration isometric rep do multiple small duration isometric practice repititions until you have learned how to do it without accidentally extending your low back

Range of motion in which the torque is maximised when no devices are used to provide resistance against forces from other directions than that from gravity

Directions for this exercise are for a lying prone position but I will compare the torque between if it was done from a standing position vs a lying prone position

The torque for doing this exercise lying prone is highest between 0 and 45 degrees of hip extension passed neutral, between 45 degrees and 180 degrees passed neutral the torque is higher when doing this exercise from a standing position instead of lying prone due to the direction of gravity

The torque while doing this exercise from a standing position is highest at 90 degrees hip extension passed neutral

The torque while doing this exercise from a lying position is greater the smaller the positive angle of extension passed neutral is as long as the right foot does not touch the floor or surface

Between 90 and 180 degrees hip extension passed neutral when doing this exercise while lying prone gravity would actually make this exercise easier but for most people the resistance from the hip flexors "not wanting" to be stretched further will be a greater force than any assistance from gravity at such a range of motion

Most people can not achieve 45 degrees hip extension passed neutral without extending their low back passed neutral so for most people it makes more sense to do this pose while lying prone than standing if torque is to be maximized and doing this exercise from a lying position provides additional benefits of being more easy to be aware of how to avoid lower back extension and avoids the difficulties involving balancing on one leg for most people

Most people should start this exercise at a low range of motion

It is better to do this exercise at less than X degrees hip extension with no practically significant amount of low back extension than fake doing this exercise at X + Y degrees with Y degrees back extension

Many people can only achieve 0 to 10 degrees of real active hip extension beyond neutral so one should be satisfied with any amount greater than 0 degrees no matter how little as long as your right knee is raised high enough to no longer touch the floor or surface

It maybe possible to do this exercise while lying prone where your right knee no longer touches the floor or surface but your right foot touches the floor or surface if dorsiflexed and still build strength if your hip extension is severely limitted in active range of motion although in such a case it might be more desirable to do other hip extensor exercises that provide more resistance and isometrically strengthen the hip extensors at 0 degrees hip extension along with additionally doing passive range of motion hip flexor strectches 

Right Knee Positions

The two ideal right knee positions when the only resistance you experience is gravity are either fully flexed or fully extended each for different reasons

The right knee can either be flexed or extended and each choice provides different advantages and disadvantages therefore eventually both should be mastered but the one you can achieve the most right hip extension with the least low back extension and or the least pain should be mastered first then the other can be mastered next

The benefit of extending the right knee will be a greater torque but the disadvantage is it avoids maximally shortening the hip extensors that also flex the knee such as the hamstrings and avoids maximally lengthening the hip flexors that also extend the knee such as the quadriceps.

The disadvantage of flexing the right knee will be less torque but the benefit is maximally shortening the hip extensors that also flex the knee such as the hamstrings and maximally lengthening the hip flexors that also extend the knee such as the quadriceps.

Things to avoid

Extending the low back beyond neutral

Rotating the hips out of neutral in the transverse plane

Biomechanical choice of position to prevent these problems

Both Shoulders abducted in the coronal plane 90 degrees with elbows straight

The left hip should not be flexed but should be either extended or neutral in the sagital plane

It does not biomechanically matter if the left knee is flexed or extended if the left foot is plantarflexed or the left foot is dorsiflexed and the knee is almost straight but not extended enough to contribute extra ground reaction force through the foot because it should not be contributing a practically different amount of torque in the transverse plane as long as the left hip is not flexed when psychological factors are not considered but psychological factors will encourage flexion of the left hip in order to extend the lower back and raise the right knee higher while reducing hip extension

It does not biomechanically matter if the neck is turned to the left or the right unless you know which way the transverse plane rotation is most likely to occur and unfortunately that is unclear because psychological factors give you a different answer than biomechanics alone

Going by biomechanics without psychological factors turning the neck to the right would help prevent transverse plane rotation but after psychological factors are considered it might make more sense to turn the neck to the left

The biomechanically most likely direction of transverse plane rotation of the pelvis is opposite the psychologically most likely direction

Biomechanically the right knee being raised provides incentive for the right pelvis to lower and the left pelvis to rise because the weight from the right leg is no longer stopped from causing rotation by the ground reaction force but the left leg's weight is mitigated by the ground reaction force

It only provides biomechanical incentive because muscles can engage to prevent this rotation and will likely engage to create rotation in the opposite direction for psychological reasons

Psychologically the right knee being raised provides incentive for the distal part of the right pelvis to raise more than the distal part of the left pelvis when the low back extends in order to raise the right leg higher while reducing the extension of the right hip, resulting in the distal part of the left pelvis being lowered relative to the distal part of the right pelvis and the distal part of the right pelvis raised relative to the distal part of the left pelvis even though both the distal part of the left pelvis and the distal part of the right pelvis are raised.  

How can the distal part of the left pelvis be raised?  By flexing the left hip.  What will most likely happen when the left hip is flexed?  The person will be be psychologically motivated to flex the left knee because it feels easier to push on the ground through the left knee with the knee flexed than to push on the ground with the left foot with the knee straight.  Why is it more difficult with the knee straight?  Because the muscles that both straighten the knee and straighten the hip are closer to active insufficiency and because the lever arm is longer.  How can you say the left knee is flexed when the left knee looks straight?  The left knee only flexes a tiny amount enough that the person pushes on the ground through their knee additionally or entirely instead of only through their foot but the knee looks almost straight

Why will the distal part of the right pelvis be raised more than the distal part of the left pelvis?  For psychological reasons to get the right knee higher.  How?  I am not sure but there are muscles available to do this.  Will it definitely happen that the distal part of the right pelvis is raised more than the distal part of the left pelvis and not the other way around every time?  No, but if I had to guess which way that is my guess because both the motive and the means are available

Psychological choice of position to prevent these problems

Psychological position to discourage rotating in the transverse plane in the direction of raising the right pelvis and loweting the left pelvis 

Turn your neck to the left rotating it in the transverse plane

Put Your right arm out shoulder flexed about 180 degrees in the sagital plane or abducted about 180 degrees in the corinal plane, elbow flexed about 90 degrees and your right hand should be to the left of your head

Left shoulder should be abducted 90 degrees in the coronal plane with the left elbow straight

The torso should remain flat and not be twisted except the rotation of the neck

Relax the left hip and keep it in neutral do not flex it

If you can not relax the left hip flexors then lightly engage the left hip extensors but only enough to prevent flexion of the left hip beyond neutral and no more because you are trying to exercise the right hip extensors only not both sides.  Engaging both sides might influence you to extend at the back which is undesirable or experience extra fatigue, pain, or discomfort or possibly get a cramp

Engage the left knee extensors if it makes it easier to disengage the left hip flexors or easier to engage the left hip extensors or easier to relax the left hip.  Else relax both the left knee flexors and left knee extensors.  Unless engaging the left knee flexor enables you to engage the left hip extensor easier and you can not relax the left hip flexors or engaging the left knee flexor relaxes the left hip flexor in which case you should engage the left knee flexor

This position of the neck and right arm works by mimicing a twist in a specific direction in the neck, arms and shoulders only but not the rest of the torso, it psychologically discourages transverse plane rotation with low back extension because raising the right pelvis in an attempt at low back extension would make the twist deeper

The position of the left arm and the right hand to the left of the head works to psychologically discourages transverse plane rotation with low back extension because raising the distal part of the right pelvis in an attempt at low back extension would make the the twist deeper since it prevents rotating the entire torso in the transverse plane to avoid the twist because it would be psychologically undesirable to abduct the left arm further in the transverse plane and if the right hand or left arm pushed down it would provide a force resisting rotation of the torso in that direction, additionally the position of the neck would make rotating the torso in such a direction also psychologically undesireable due to the urge not to rotate the neck  or head more than 90 degrees in the transverse plane

The position of the right shoulder being abducted 180 degrees in the coronal plane makes rotating the torso in the the transverse plane to the opposite direction to that which is psychologically desirable easier than if it was abducted 0 degrees or 90 degrees

Copyright Carl Janssen 2022