Kinematics Flashcards
Kinematics of Swimming - Entry Phase
External and internal obliques provide rotation of the trunk and hips.
Glues maximus and hamstrings allow hip extension and knee flexion of the entry side leg.
The foot and toes are plantar flexed.
The trunk is stabilized by the lumbar and thoracic stabilizers, quadratus lumborum, rectus and transverse abdominals.
The cervical paraspinals, upper trapezius, levator scapula and deep neck flexors stabilize head and neck.
The wrist flexors and extensors stabilize the hand to stay flat and natural.
Triceps are concentrically contracting to extend elbow.
The anterior deltoid concentrically contracts to provide shoulder flexion.
The serratus anterior protracts the shoulder blade aiding in the extension of the reach.
Kinematics of Swimming - Catch Phase
The hip flexiors, adductors and quadriceps concentrically contracts to initiate hip flexion and knee extension.
Tibialis anterior dorsiflex ankle.
External and internal obliques begin to rotate the trunk and hips to the opposite side.
During rotation thoracic paraspinals, quadratus lumborum, rectus and transverse abdominals continue to stabilize the trunk.
To press backwards, the pectoralis major, latissimus dorsi and posterior deltoid initiate shoulder extension.
The serratus anterior and upper trapezius continue to protract shoulder blade.
The shoulder is stabilized by lower trapezius, rhomboids and subscapularis.
If taking a breath, the neck rotates to the sam side as pulling arm. Otherwise the neck stays neutral.
In the catch phase, the wrist flexes while elbow extends. At the same time, latissimus dorsi and subscapularis internally rotate the shoulder.
Kinematics of Swimming - Pull Phase
The iliopsoas and rectus femoris provide hip flexion. The quadriceps contract, extending the knee. The ankle dorsiflexion continue to contract concentrically to create downward force.
From the pulling side the internal oblique contracts, while on the opposite side, the external oblique contracts, rotation the trunk towards the pulling arm.
The rhomboids, middle and lower trapezius act as a primary mover to move elbow from flexed to extend position.
In the pull phase the palm is facing back wall and fingertips are facing downwards. Biceps and brachioradialis contract to flex the elbow.
Kinematics of Swimming - Recovery Phase
In the recovery phase the biceps concentrically contract to move the elbow from the an extended position to flex position. The posterior deltoid and triceps lift the hand out of water, while the biceps continue to flex the elbow
The shoulder continue extension with additional abduction and external rotation as the arms moves higher.
Scapula stays in retraction.
The shoulder are of anterior and medial deltoid, pectoralis major and coracobrachialis concentrically contract to move the arm forward toward the front of the body.
The serratus anterior retract scapula. As the arm moves to the front of the body, triceps begin to extend the elbow.
The same side internal obliques and recovery side external obliques rotate the trunk to the opposite side.
Kinematics of Cycling - Downstroke
Start at the top of the stroke, or 0 degree, and moves toward the bottom of the stroke, or 180 degree.
Between 0 and 90 degree the goal is to push down and forward. Gluteus maximus and hamstrings are the primary movers, initiating movement by extending the hip.
Guadtriceps will concentrically contract to extend the knee which assist in bringing the foot forward.
Plantar flexors of the ankle will start to push downward on the pedal. The anterior tibialis counterbalances the plantar flexors. The ankle is in a neutral position, driving the heel to the ground.
From 90 to 180 degree the quadriceps and hamstrings become the primary movers. The quadriceps continues to extend the knee and hamstrings extends the hip. The plantar flexor increase they activity while push down to the pedal, reaching peak muscle activity at 110-130 degree. At the bottom of the stoke there should be about 10-15 degree flexion at the knee. Knee is never fully extended.
Kinematics of Cycling - Backstroke
The backstroke takes place between 135 - 225 degree and it’s a transition between downstroke and upstroke/The athlete should be dragging the foot across the bottom of the stroke. The hamstrings contracts providing the dragging of the foot. This provides hip extension and knee flexion. The anterior tibialis provides ankle dorsiflexion via concentric contraction.
Kinematics of Cycling - Upstroke
It’s the movement from 180-360 degree. The hip and knee begin to flex, and heel begins to rise. The cyclist pull the hip and foot to the top of the stroke in a relaxed manner. The cyclist shouldn’t push down on the pedal because it creates counter force to the opposite leg going through the downstroke.
Just prior to 270 and and continuing till 360 degrees, the iliopsoas, rectus femoris and sartorius initiate and perform hip flexion. The anterior tibialis activates to dorsiflex the ankle. The cyclist is trying to lift the foot over to the top of the stroke, keeping the heel slightly higher then the bottom of the foot as it comes higher. By the top of stroke, the foot is nearly neutral.
Kinematics of Cycling - Overstroke
The purpose of overstroke is to get the foot over the top of the pedal stroke and to begin the downstroke. It starts around 315 degrees and ends past 0 degrees.
The iliopsoasm rectus femoris and sartorius, also known as hip flexors, continue to flex the hip. The anterior tibialis provides dorsiflexion of the ankle until the top of the pedal stroke at 360 degree.
As the foot crosses the top, hamstrings and gluteus maximus initiate hip flexion into the downstroke.
Kinematics of Cycling - Stabilization
The gluteus minimus and medius provide concentric abduction and external rotation forces and prevent the valgus and varsus movements at the knees. This means the knees are kept from driving inward to the top tube (valgus movement) and outward away from the top tube (varsus movement).
The cyclist should keep the trunk and pelvis as stable as possible during the pedal stroke, with all energy and force going to the pedals. Without stable base for the legs, the muscle will not be able to work with appropriate efficiency. Unbalance base creates aberrant motions at the hip and knees which can lead to injury.
The rotator cuff, latissimus dorsi and pectoralis major provide stabilization for the shoulder and upper arm, while the elbow is stabilized by the co-contraction of biceps and triceps.
While in the aero position or sitting up on the seat, with flexion at the lumbar spine and the anterior tilt of the pelvis, the lumbar and thoracic paraspinals, quadratus lumborum, obliques, transverse abdominis and rectus abdominis co-contract to stabilize he trunk and pelvis.
The cervical paraspinals, upper trapezius, levator scapula, scalenes, sternocleidomastoid and eep neck flexors stabilize the neck.
The middle and lower trapezius , rhomboids and serratus provide stabilization or the anterior trunk and scapula.
Kinematics of Running - Initial contact / loading response
Initial contact / loading response marks when foot comes into contact with ground and the support limb begins to accept the weight. The foot should strike lose to the centre of mass, just anterior of the hip and joint and pelvis.
The ankle is in a plantar flexed position. Regardless of foot strike, the anterior tibialis, extensor digitorum longus, and extensor hallucis longus eccentrically contract on lowering the foot to the ground. During the loading response the lower leg begins moving over the ankle toward dorsiflexion. Anterior tibialis, extensor digitorum longus, and extensor hallucis longus concentrically start this movement. The plantar flexors begin to fire eccentrically late in the loading response to control movement of the lower leg over the ankle.
The knee is in a slightly flexed position. The quadriceps concentrically contract as the limb accepts weight. The quadriceps create an extensor moment to counter the ground reaction forces. The hamstring acts eccentrically, contracting to counter attack the amount of knee extension. As the runner moves into loading response, the quadriceps begin to eccentrically contract to prevent the knee from collapsing.
The runner’s hip is in a flexed position in front of the center of mass. The hamstrings and gluteus maximus are eccentrically contracting to control the flexion movement of the hip from the swing phase. Going into loading the limb, the gluteus maximus and hamstring continue to eccentrically contract and begin initiation of the hip extension.
Kinematics of Running - Mid Stance
In mid stance, the upper trunk moves over the support limb and continues just prior to the support limb’s heel coming off the ground.
The hip moves from a flexed position in the loading response to an extension position as the lower leg moves over the ankle. This allows the center of mass to be moving over the foot. Early in mid stance, the gluteus maximus concentrically contracts to move the hip into extension. The gluteus medius and minimus stabilize the pelvis in the frontal plane.
The knee continues in a slight flexed position, and the quadriceps continues its eccentric contraction to stabilize the knee. The hamstrings become concentrically active in late mid stance to prepare for terminal stance.
The lower leg continues to move over the ankle, creating a dorsiflexion moment. The gastrocnemius and soleus eccentrically control the tibia and fibula over the ankle. The posterior tibialis tendon, flexor digitorum longus, flexor hallucis longus and peroneus longus and peroneus brevis stabilize the foot.
Kinematics of Running - Terminal Stance
The terminal phase begins as the heel comes off the ground, with the trunk moving ahead of the foot.
Initially, as the lower leg moves over the ankle with knee flexion, the plantar flexors eccentrically control this movement, and then isometrically contract to assist with the heel coming off the ground. The plantar flexors transition to concentric contraction to promote the push-off at the end of terminal stance.
The knee begins flexion through the concentric contraction of the hamstrings. This flexion facilitates plantar flexion of the ankle.
The hip moves into further extension via the concentric contraction of the gluteus maximus. The hip adductors eccentrically contract to control the amount of hip extension.
Kinematics of Running - Initial Swing
The initial swing phase begins with the runner lifting the foot from the ground and ends when the swing leg is even with the stance leg.
The hamstrings mildly activate to promote knee flexion. The ankle moves from plantar flexion at push-off to ankle dorsiflexion by the anterior tibialis, extensor digitorum longus and extensor hallucis longus.
The concentric contraction of the iliopsoas, rectus femoris, sartorius and hip adductors initiate the forward flexion of the hip.
Kinematics of Running - Mid Swing
During mid swing, the swing leg is even with the opposing stance leg and continues to move the lower leg forward until the tibia is vertical to the ground. Important aspects of the mid swing are forward movement of the swing leg and foot clearance.
The anterior tibialis, extensor digitorum longus and extensor hallucis longus provide ankle dorsiflexion for foot clearance. The mild contraction of the hamstrings continues to promote knee flexion and assist with foot clearance.
The iliopsoas, rectus femoris and sartorius continue the concentric action of hip flexion. The hamstrings eccentrically activate late in mid swing to control the forward movement of the lower leg.
Kinematics of Running - Terminal Swing
During the terminal swing phase, the swing limb decelerates and prepares to strike the ground at initial contact.
The quadriceps contracts to provide a small extension of the knee. The hamstrings eccentrically contract to control the deceleration of the lower limb and prevent full knee extension. The anterior tibialis group begins eccentric contraction to lower the foot as it prepares for the foot strike.
At the hip, the gluteus maximus eccentrically contracts to decelerate the forward-moving hip.
