Post by Mr. Espey on Feb 9, 2006 1:28:21 GMT -5
BY BRIAN KEHLER:
I did a movement analysis of the Deadlift for my Kinesiology course project, broken down into the 5 phases. If anyone is interested here it is:
The movement I have chosen for my analysis is the deadlift. There are many different variations to this movement based on performance, goals, competition rules as well as personal preference.
I am focusing on a regular stance deadlift, with the guidelines of IPF ruling, double overhand grip with a 1RM in mind.
The Deadlift
1. stand behind the bar, so that it is over the balls of your feet.
2. keep feet shoulder width apart, pointing forwards or slightly outwards.
3. bend down with legs straight and grasp the bar, hands slightly greater than shoulder width apart.
4. squat down so that thighs are approximately parallel to the ground, back straight, and eyes looking forward.
5. keeping the back rigid and arms straight and shoulder forward, lift the bar using the legs, keeping the bar as close to the body as possible.
6. when standing upright, complete the lift by pulling the shoulders back and shifting the center of gravity to the heels for a 1 count.
7. return bar to ground using a controlled technique.
The saying for deadlifts is “Grip, Dip and Rip”, and is performed in one fluent movement so as not to waste any extra energy on setup, but rather focus on the lift.
#1) Skill Breakdown – The 5 Phases
Preliminary Movements
This involves the portion of the movement where the lifter comes to the platform to the bar which is already loaded with their desired attempt weight. After stepping onto the platform the judge will say “Lift when ready”. The lifter will position himself in front of the bar and establish his stance width, bend over with legs straight and establish his grip on the bar. He will then take a large breath and hold it. This immediately leads to………
Backswing/Recovery
At this point the lifter will dip down into a squat position with thighs just above parallel to the floor, back is flat at 45 degrees to the floor, shoulders are forward, the arms are straight and locked out at the elbow, head is up with eyes forward. This immediately leads into………
Force Producing Phase
The lifter explodes upwards out of the hole with the legs, keeping the bar as close to the body dragging it up his shins, at this point there is some extension of the spine. Once the bar is at the level of the knee the lifter starts extending the back more to pull the bar up to mid-thigh level, while his legs become straight and spine becomes fully extended. This leads to……..
Critical Instant
Once the lifter is fully erect with legs straight and spine fully extended, he shifts the weight back onto the heels and retracts his shoulders and holds the lockout position until the judge gives the signal to lower the weight. And finally this leads to…
Follow Through
This is where the lifter lowers the weight in a controlled fashion back down to the platform and waits for the judge’s decision to see if the lift was successful and exits the platform area.
#2) Joints – Plane of Motion & Axis of Rotation
Ankles – the ankle joint goes into passive dorsi-flexion when lowering the body in the backswing phase, upon coming up in the force production phase the ankle comes into plantar flexion to restore the joint to it’s neutral position. The movement occurs in the saggital plane, and around the Left-Right axis of rotation.
Knees – the knee joint starts in extension, and eccentrically goes into flexion when in the backswing phase, upon beginning the force production phase the knee returns to full extension, this again occurs in the saggital plane, and around the Left-Right axis of rotation.
Hips – The hips are in a position of flexion at the bottom of the backswing, as well as the pelvis is rotated anteriorly, when coming back up in the force production phase the hips are becoming fully extended and the pelvis rotated posteriorly. This is occurring in the saggital plane and around the Left-Right axis of rotation.
Trunk – The trunk begins in flexion in the backswing phase, and in this movement there is considerable loading on the spine, upon extension of the spine there is compression and tension forces, which is why it is important to keep the bar close to the body to minimize this. This occurs in the saggital plane and around the Left-Right axis of rotation.
Shoulders - In the movement there really isn’t any main function except as an anchor point for the weight to the body. The only movement occurring is retraction at the critical instant to shift the weight over the heels which would occur in the saggital plane. There is also some shoulder extension coming into play in order to keep the bar close to the body throughout the movement, and this occurs in the Left-Right axis of rotation.
Elbows & Wrists – Both structures are simply accessory structures, and don’t have any movement. They hold the tension forces coming from the weight being held by the hands.
#3) Identifying Muscles
During the Back Swing:
Agonists – Gluetus maximus, vastus lateralis/intermedius/medialis, gastrocnemius, soleus, spinal erectors.
Antagonists – Psoas major, iliacus, hamstrings, tibialis anterior.
Synergists –
Stabilizers – erector spinae, abdominals
During Force Production & Follow Through:
Agonists - Gluetus maximus, vastus lateralis/intermedius/medialis, gastrocnemius, soleus, spinal erectors, trapezius (all fibers), rhomboids, rear deltoids.
Antagonists - Psoas major, iliacus, hamstrings, tibialis anterior, pec major and minor, serratus anterior.
Synergists – hamstrings, lateral rotators, adductors
Stabilizers – erector spinae, abdominals, deltoids, rotator cuff
-----------------------------------------
During the force producing phase, the hamstrings are an antagonist, but to a degree they are also a synergist. They have to allow the quads to contract concentrically, but help the hips remain stable during extension, hence why the hamstrings are taut during the force producing phase even though the quads are contracting.
A problem with deadlifts that some have is the knees buckling inward or outwards during the lift. This is where lateral rotators and adductors come into play as synergists because they keep the knees in a fixed position while the lift is being executed.
Abdominal muscles work as a powerful stabilizer through the movement to keep inter-abdominal pressure high to help keep the spine stable against forces,
The forearm flexors and extensors also come into play gripping the bar, to stabilize the wrist, and help maintain force to grasp the bar firmly. Hand strength is often the weakest point among lifters and they cannot hold the weight.
#4) More concepts involved.
-The principle behind the deadlift is “Grip, Dip, and Rip”. The reason this works is because of the Stretch shortening cycle. A mistake many beginners make during their setup is spending too much time taking their grip and getting ready to lift in the squatted position. This not only burns up energy and strength but it causes fatigue to set in much earlier than it normally would, leading to sub-maximal lifts and poor results. By incorporating the stretch shortening cycle, it enables the lifter to capitalize on the elastic properties. The stored elastic energy from the eccentric lowering phase is followed immediately by the force producing phase releasing stored elastic energy to “Rip” the bar off the floor.
-A lot of lifters at the elite level will choose to wear a belt or a deadlift suit (also known as erector suits), or both. By doing this they dramatically increase compression around the core area and in the spine to prevent injury as well as mild relief from fatigue. The erector suit helps to pull the spine into extension to relieve both tension and compression forces. Some consider this cheating by getting returns from equipment that can help you lift more, but at the level of competition and the weights being moved, all lifters are using some form of equipment.
- Another variable in this movement is the grip being used. There are some lifters who still opt out for an over/under grip (one hand supinated, the other pronated). The reason behind using such a grip is to prevent rotation of the bar. In competition this grip is being used less because of safety issues. It can increase rotation of the spin and torsion forces which can lead to injury if any part of the lift goes wrong. The grip is not banned, however.
- Many lifters will choose to cover their shins and thighs with baby powder to increase velocity of the bar up the shins, and create less friction over the thighs. Hitching is when a lifter rests the bar on his thighs and jerks it up. This is not allowed in sanctioned events and every advantage to increase bar speed is used.
- Finally, when training for the deadlift, many different methods are used. My personal favorite is using Jump Stretch bands over the ends of the bar for dynamic training. The weight used is lighter, so you can explosively more the bar off the floor, then when you hit the thigh level, the weight is increased dramatically. This can also be done with chains hanging off the ends of the bar. One more method is pulling off boxes, so you have to get lower. Then by returning to normal bar height, the distance the bar needs to travel will be less, and you will be stronger from the starting point. These are all incorporated into conjugated training methods.
I did a movement analysis of the Deadlift for my Kinesiology course project, broken down into the 5 phases. If anyone is interested here it is:
The movement I have chosen for my analysis is the deadlift. There are many different variations to this movement based on performance, goals, competition rules as well as personal preference.
I am focusing on a regular stance deadlift, with the guidelines of IPF ruling, double overhand grip with a 1RM in mind.
The Deadlift
1. stand behind the bar, so that it is over the balls of your feet.
2. keep feet shoulder width apart, pointing forwards or slightly outwards.
3. bend down with legs straight and grasp the bar, hands slightly greater than shoulder width apart.
4. squat down so that thighs are approximately parallel to the ground, back straight, and eyes looking forward.
5. keeping the back rigid and arms straight and shoulder forward, lift the bar using the legs, keeping the bar as close to the body as possible.
6. when standing upright, complete the lift by pulling the shoulders back and shifting the center of gravity to the heels for a 1 count.
7. return bar to ground using a controlled technique.
The saying for deadlifts is “Grip, Dip and Rip”, and is performed in one fluent movement so as not to waste any extra energy on setup, but rather focus on the lift.
#1) Skill Breakdown – The 5 Phases
Preliminary Movements
This involves the portion of the movement where the lifter comes to the platform to the bar which is already loaded with their desired attempt weight. After stepping onto the platform the judge will say “Lift when ready”. The lifter will position himself in front of the bar and establish his stance width, bend over with legs straight and establish his grip on the bar. He will then take a large breath and hold it. This immediately leads to………
Backswing/Recovery
At this point the lifter will dip down into a squat position with thighs just above parallel to the floor, back is flat at 45 degrees to the floor, shoulders are forward, the arms are straight and locked out at the elbow, head is up with eyes forward. This immediately leads into………
Force Producing Phase
The lifter explodes upwards out of the hole with the legs, keeping the bar as close to the body dragging it up his shins, at this point there is some extension of the spine. Once the bar is at the level of the knee the lifter starts extending the back more to pull the bar up to mid-thigh level, while his legs become straight and spine becomes fully extended. This leads to……..
Critical Instant
Once the lifter is fully erect with legs straight and spine fully extended, he shifts the weight back onto the heels and retracts his shoulders and holds the lockout position until the judge gives the signal to lower the weight. And finally this leads to…
Follow Through
This is where the lifter lowers the weight in a controlled fashion back down to the platform and waits for the judge’s decision to see if the lift was successful and exits the platform area.
#2) Joints – Plane of Motion & Axis of Rotation
Ankles – the ankle joint goes into passive dorsi-flexion when lowering the body in the backswing phase, upon coming up in the force production phase the ankle comes into plantar flexion to restore the joint to it’s neutral position. The movement occurs in the saggital plane, and around the Left-Right axis of rotation.
Knees – the knee joint starts in extension, and eccentrically goes into flexion when in the backswing phase, upon beginning the force production phase the knee returns to full extension, this again occurs in the saggital plane, and around the Left-Right axis of rotation.
Hips – The hips are in a position of flexion at the bottom of the backswing, as well as the pelvis is rotated anteriorly, when coming back up in the force production phase the hips are becoming fully extended and the pelvis rotated posteriorly. This is occurring in the saggital plane and around the Left-Right axis of rotation.
Trunk – The trunk begins in flexion in the backswing phase, and in this movement there is considerable loading on the spine, upon extension of the spine there is compression and tension forces, which is why it is important to keep the bar close to the body to minimize this. This occurs in the saggital plane and around the Left-Right axis of rotation.
Shoulders - In the movement there really isn’t any main function except as an anchor point for the weight to the body. The only movement occurring is retraction at the critical instant to shift the weight over the heels which would occur in the saggital plane. There is also some shoulder extension coming into play in order to keep the bar close to the body throughout the movement, and this occurs in the Left-Right axis of rotation.
Elbows & Wrists – Both structures are simply accessory structures, and don’t have any movement. They hold the tension forces coming from the weight being held by the hands.
#3) Identifying Muscles
During the Back Swing:
Agonists – Gluetus maximus, vastus lateralis/intermedius/medialis, gastrocnemius, soleus, spinal erectors.
Antagonists – Psoas major, iliacus, hamstrings, tibialis anterior.
Synergists –
Stabilizers – erector spinae, abdominals
During Force Production & Follow Through:
Agonists - Gluetus maximus, vastus lateralis/intermedius/medialis, gastrocnemius, soleus, spinal erectors, trapezius (all fibers), rhomboids, rear deltoids.
Antagonists - Psoas major, iliacus, hamstrings, tibialis anterior, pec major and minor, serratus anterior.
Synergists – hamstrings, lateral rotators, adductors
Stabilizers – erector spinae, abdominals, deltoids, rotator cuff
-----------------------------------------
During the force producing phase, the hamstrings are an antagonist, but to a degree they are also a synergist. They have to allow the quads to contract concentrically, but help the hips remain stable during extension, hence why the hamstrings are taut during the force producing phase even though the quads are contracting.
A problem with deadlifts that some have is the knees buckling inward or outwards during the lift. This is where lateral rotators and adductors come into play as synergists because they keep the knees in a fixed position while the lift is being executed.
Abdominal muscles work as a powerful stabilizer through the movement to keep inter-abdominal pressure high to help keep the spine stable against forces,
The forearm flexors and extensors also come into play gripping the bar, to stabilize the wrist, and help maintain force to grasp the bar firmly. Hand strength is often the weakest point among lifters and they cannot hold the weight.
#4) More concepts involved.
-The principle behind the deadlift is “Grip, Dip, and Rip”. The reason this works is because of the Stretch shortening cycle. A mistake many beginners make during their setup is spending too much time taking their grip and getting ready to lift in the squatted position. This not only burns up energy and strength but it causes fatigue to set in much earlier than it normally would, leading to sub-maximal lifts and poor results. By incorporating the stretch shortening cycle, it enables the lifter to capitalize on the elastic properties. The stored elastic energy from the eccentric lowering phase is followed immediately by the force producing phase releasing stored elastic energy to “Rip” the bar off the floor.
-A lot of lifters at the elite level will choose to wear a belt or a deadlift suit (also known as erector suits), or both. By doing this they dramatically increase compression around the core area and in the spine to prevent injury as well as mild relief from fatigue. The erector suit helps to pull the spine into extension to relieve both tension and compression forces. Some consider this cheating by getting returns from equipment that can help you lift more, but at the level of competition and the weights being moved, all lifters are using some form of equipment.
- Another variable in this movement is the grip being used. There are some lifters who still opt out for an over/under grip (one hand supinated, the other pronated). The reason behind using such a grip is to prevent rotation of the bar. In competition this grip is being used less because of safety issues. It can increase rotation of the spin and torsion forces which can lead to injury if any part of the lift goes wrong. The grip is not banned, however.
- Many lifters will choose to cover their shins and thighs with baby powder to increase velocity of the bar up the shins, and create less friction over the thighs. Hitching is when a lifter rests the bar on his thighs and jerks it up. This is not allowed in sanctioned events and every advantage to increase bar speed is used.
- Finally, when training for the deadlift, many different methods are used. My personal favorite is using Jump Stretch bands over the ends of the bar for dynamic training. The weight used is lighter, so you can explosively more the bar off the floor, then when you hit the thigh level, the weight is increased dramatically. This can also be done with chains hanging off the ends of the bar. One more method is pulling off boxes, so you have to get lower. Then by returning to normal bar height, the distance the bar needs to travel will be less, and you will be stronger from the starting point. These are all incorporated into conjugated training methods.
