Locomotion Flashcards
What is the locomotor system?
Musculoskeletal system of the skeleton, muscles and connective tissue to enable movement.
What are the advantages of the bipedal system?
Frees our hands, allows us to elevate our heads and navigate challenging terrain.
What are the disadvantages?
Less energetically efficient and stable than a quadrapedal system.
What is the gait cycle?
Sequence of events between the heel strike of an ipsilateral foot. It is divided into a stance phase and a swing phase.
What are the phases of the gait cycle?
Stance phase and swing phase.
What is the stance phase?
60% of the gait cycle. The limb has contact with the ground. Begins with a heel strike, then mid-stance, loading response and propulsion from the toe in the terminal stance.
What is the swing phase?
40% of the gait cycle where the limb does not have contact with the ground. Begins with propulsion from the toe and ends with a heel strike. Divided into pre-swing, initial swing, mid-swing and terminal swing.
What is the difference between a step and a stride?
A step is the distance between a heel strike on contralateral legs. A stride is the gait cycle and the distance between the heel strike on an ipsilateral leg.
What is the difference between walking and running?
One limb always has contact with the ground in walking and acts as an inverted pendulum to propel forwards. During running, energy is stored in tendons and released as controlled leaps which allows both limbs to have simultaneous zero ground contact.
What are the phases of the running gait?
Stance phase, swing phase and double leap.
What is the stance phase in the running gait?
Accounts for only 40% of running. Includes impact where heel strike absorbs force and drive via toe to propel the lower leg.
What is the double float phase in running?
Phase during running where there both limbs have no contact with the ground.
What is the swing phase in running?
60% of the running gait where one limb has contact wih the ground. There is recovery, pre-swing, intial swing, midswing and then the terminal swing to leap.
What are the components of the locomotor system?
Bones and joints
What are joints?
Points where two bones make contact and classified based on their range of motion. Synarthrosis are immovable, amphiarthroisis are slightly movable and diarthrosis have a full range of motion.
What are the types of joints in the locomotor system?
Ball and socket joint, pivot joint, ellipsoidal joint and hinge joint.
What is the ball and socket joint?
Diarthrosis synovial joint which has a full range of notion in all directions. This is found in the hip joint and the shoulder joint.
What is the pivot joint?
Diarthrosis synovial joint that allows movement around a single point like a wheel. This is found between C1 and C2 vertebrae to turn the head. It is found between the radius and ulna to twist the forearm.
What is the ellipsoidal joint?
Diarthrosis synovial joint that allows movement laterally and front to back. This is found in the joints of the knuckles, wrist, metacarpophalangeal joints (fingers) and metatarsophalangeal joints (toes).
What is the hinge joint?
Diarthrosis synovial joint which allows movement only flexion and extension. It is found in the knee, elbow and angle.
What is torque?
It is the rotational force of a bone around a joint, generated by the contraction of an attached muscle.
What is a concentric muscle?
Contraction to overcome resistance which shortens the muscle
What is the eccentric muscle?
Contraction to overcome resistance however it cannot which causes the lengthening of the muscle.
What is an agonist and antagonist?
Agonist muscle induce movement by contraction such as the bicep muscle. Antagonist muscle oppose movement through contraction such as the tricep.
What is a muscle lever?
A rod like a bone that turns around a joint to generate a force.
What are the components of a lever?
The load which is the weight, the road which is the bone, the joint and the effort which is the muscle
What is a muscle moment?
It is the perpendicular distance between the joint and the line of muscle action.
How does distance affect torque?
By increasing the moment, it will mean that more torque/rotational force will need to be applied.
How are bodies adapted for speed?
Low muscle moment so less force is required.
How are bodies adapted for strength?
High muscle moment so more force is required.
What are tendons?
Connective tissue which connects muscle to bone.
Difference between tendons and ligamnets?
Ligaments are connective tissue which connects bone to bone. Tendon are connective tissue which connects muscle to bone.
Where does muscle activation occur?
The primary motor cortex in the cerebrum.
What is the role of the gluteus medius and minimus?
Abductor muscles of the thigh which attach to the iliac blade of the greater trochanter
What is the role of gluteus maximus?
Extensor muscle which pulls the leg back.
What is the sartorius?
Flexion and abduction for lateral rotation of the thigh.
What is the quadriceps?
It is responsible for flexion of the thigh and extension of the knee.
What is the hamstrings?
It is responsible for the extension of the thigh and flexion of the knee.
Which muscles are involved in plantar flexion?
Gastronemius, soleus and plantaris
What is the role of the tibialis anterior?
Dorsiflexion.
What is the centre of mass?
Centre of mass is in the middle of the pelvis anterior to the second sacral vertebrae. It is part of the load in the lever where it acts downward along with our mass, which is counteracted by joints and the line of muscle action.
How are humans stable?
The position between their centre of mass in the pelvis over the base of support.
What is the ankle and hip strategy?
The stability generated by dorsiflexion and plantarflexion when our hips move forwards and backwards. This occurs unconsciously to keep us balanced.
What is the disadvantage of bipedalism?
Energetically unfavourable because it requires use of the hamstrings, quadriceps and gluteus maximus to stay upright.
What affects gait?
Structural damage to the musculoskeletal system involved in the walking and running phases, such as nerves, blood supply, bones or muscle damage.
How does aging affect gait?
Lower muscle mass and flexibility therefore there is more steps taken to compensate for a shorter stride length
How does footwear affect gait?
Flat shoes increases ankle length and reduces heel impact. High heels causes shortening of the calf muscle and achilles tendon.
How does arthritis affect gait?
Causes antalgic gait where patient will avoid placing weight on the affected area.
How do neurological disorders affect gait?
Brain motor control is in the cerebrum and cerebellum for fine movement. Parkinson’s, peripheral nerve disease and multiple sclerosis are examples of affected gait.
What is ataxic gait?
Unstable unbalanced gait, usually an indicator of issues with the cerebellum which can be inhibited with alcohol consumption.
What is antalgic gait?
Avoiding placing weight on the affected area that leads to longer swing phase, longer steps and shorter stride.
What is myopathic gait?
Duck waddle gait caused by weakening of the pelvic girdle muscles.
What is neuropathic gait?
When a disorder such as peripheral nerve disease affects the brain and leads to a high stepping gait.
How are the hips and pelvis adapted for bipedalism?
Shorter pelvis which is wider vertically. Wide ileum reduces the distance from the sacroiliac joint and load when shifting weight.
How is the iliac blade adapted?
Wider and more curved for attachment for the gluteus medius muscles to act as hip abductors for preventing trunk swaying when walking or running
How is the femur adapted for bipedalism?
Larger head and diagonal disposition supports weight bearing.
What is coxa vara?
Reduced angle of less than 120 degrees which leads to shortening of the limb- commonly associated with fractures.
What is coxa valga?
Femoral head angle is more than 140 caused by weakness of the adductor muscles that affects the weight bearing and is generally associated with neurological conditions.
How is the knee adapted for bipedalism?
Locking mechanism that brings the tibiual and femoral condyle close together and the anterior cruciate ligament and to be tensed for stability.
How is the foot adapted for bipedalism
Medial and lateral longitudinal arch which is important for shock absorbing and transferring weight.
How is the vertebrae adapted for bipedalism?
Curved, especially in the cervical and lumbar to distribute weight to the lower limbs.
What is the role of the iliofemoral ligament?
Limits backwards bending of the trunk.
What is pes planus?
Longitudinal arch of the foot has fallen caused by standing for long periods of time or being overweight.
