Musculoskeletal System Flashcards
What is concentric contraction?
Shortening of muscle fibres; insertion moves towards origin
Concentric contractions are often involved in lifting movements.
What is isometric contraction?
Force generated to keep muscle fibres at the same length
Isometric contractions occur when the muscle exerts force without changing length.
What is eccentric contraction?
Force is applied but there is a lengthening of muscle fibres
Eccentric contractions are commonly involved in lowering movements.
In concentric contraction, what happens to the muscle fibres?
They shorten
This occurs during actions like lifting weights.
In isometric contraction, what happens to the muscle fibres?
They maintain the same length
This is seen in exercises like wall sits.
In eccentric contraction, what happens to the muscle fibres?
They lengthen
This type of contraction is crucial for controlling movements.
True or False: Concentric contraction results in muscle elongation.
False
Concentric contraction leads to muscle shortening.
Fill in the blank: In _______ contraction, the muscle does not change length despite the application of force.
isometric
Isometric contractions are essential for stabilizing joints.
What type of muscle contraction occurs when the insertion moves towards the origin?
Concentric contraction
This movement usually occurs during lifting activities.
What are the 4 main functions of the musculoskeletal system
Locomotion
Stabilisation of joints
Maintaining posture
Production of body heat
What is the definition of a stride
The distance between initial contact with one leg and contact again with the same leg
What is the definition of a step
The distance between initial contact with one leg and initial contact with the opposite leg
What is the definition of cadence
Number of steps per minute
A _______ is the distance between initial contact with one leg and initial contact with the opposite leg
Step
A _____ is the distance between initial contact with one leg and contact again with the same leg
Stride
______ is the number of steps per minute
Cadence
What position is the hip in during initial contact
Hip is flexed
What position is the knee in during initial contact
Knee is extended
What position is the ankle in during initial contact
Ankle is dorsiflexed
What happens during initial contact and what muscles are being used
Right leg slowly decelerates- carried out by gluteus maximus and hip extensors- gluteal region
Right forefoot starting to be lowered to the ground- carried out by eccentric contraction of ankle dorsiflexors- the anterior compartment of the leg
What is the second step after initial contact in the gait cycle known as
Loading response
What is the first step in the stance phase of gait cycle known as
Initial contact
What happens during the loading response
Right knee and leg accept body weight via knee extensors- anterior compartment of the thigh
Right foot decelerates as it lowers- ankle plantarflexors- posterior compartment of leg
Stabilisation of pelvis- left leg now in air- prevents pelvis dropping on left side- ipsilateral hip abductors
What is the third step of the gait cycle
Midstance
What occurs during midstance
Mostly the same as loading response
However now knee extensors act to stabilise knee- anterior compartment of the thigh
What step is after midstance in the gait cycle
Terminal stance
What occurs during terminal stance in the gait cycle
Heel lifted off the floor- plantarflexors- posterior compartment of leg
Propel leg forward
What step is after terminal stance
Pressing
What occurs during preswing in the gait cycle
Flexion of toes- posterior compartment of leg
What comes after the stance phase in the gait cycle
The swing phase
What’s the first step of the swing phase in the gait cycle
Initial swing
What occurs during initial swing in the gait cycle
Foot cleared from the floor- ankle dorsiflexors- anterior compartment of leg
Knee flexes due to momentum
Acceleration of leg forward- hip flexors- anterior compartment of thigh
What step occurs after initial swing
Mid swing
What occurs during mid swing
Ankle continues to be cleared from floor- dorsiflexion of ankle- anterior compartment of leg
What is the third step of the swing phase
Terminal swing
What occurs during the terminal swing
Deceleration in order to step on foot
Eccentric contraction of hip extensors- gluteal region and posterior thigh
Knee extension- anterior compartment of thigh
Foot position- ankle dorsiflexion
What are the 3 types of abnormal gait
Antalgic
Trendelenburg
Foot drop- high steppage/ slapping gait
Why does antalgic gait arise
Occurs secondary to pain in the lower limb
How does antalgic gait affect stance phase
Less time spent in stance phase on affected side- so less weight put on affected leg
How does an antalgic gait affect swing phase
Swing phase in unaffected leg shortened
Describe what an antalgic gait looks like and why it occurs
Occurs secondary to lower limb pain
Less time in stance phase on affected side
Less time in swing phase on unaffected side
Physically looks like a limp
Why does foot drop arise
Due to loss of muscles in the anterior compartment of the leg- causes little to no dorsiflexion of the ankle
Can be due to damage to deep peroneal nerve or common peroneal nerve/ disc herniation
What does foot drop look like
Struggle to clear toes off ground- lifts leg higher
Causes high steppage or dragging foot on ground
When weight placed on foot- struggle to control it- foot slaps onto ground- ‘foot slap’
Describe what foot drop looks like and why it arises
Loss of muscles in anterior compartment of leg- causes loss of dorsiflexion- due to damage too deep peroneal nerve or common P nerve/ disc herniation
Means foot doesnt clear floor- either high steppage or foot drags
Foot slaps ground- foot slap- when weight put on foot due to lack of control
What causes trendelenburg gate to arise
Superior gluteal nerve palsy or damage to muscles post surgery
Causes loss of function of hip abductors- gluteus medius and minimus
How does trendelenburg gait affect pelvis movement
During stance phase in a normal gait when leg is off ground the hip abductors keep pelvis level
Trendelenburg- gluteus medius and minimus non functional- cant keep pelvis level -pelvis drops to side of lifted leg
Describe how trendelenburg looks like and why it arises
Hip drop to side of lifted leg- due to loss of function of hip abductors- gluteus medius and minimus- caused by superior gluteal nerve palsy or damage to muscles post surgery
