Kinesiology

Question 1

What is a spurt muscle

Answer 1

Insertion is closer to the joint than the origin, muscle force mainly acts to rotate the bone
E.g. biceps in elbow flexion

Question 2

What is a shunt muscle

Answer 2

Origin is closer to the joint than the insertion, muscle force is directed along the bone
E.g. brachiordialis

Question 3

What is active insufficiency

Answer 3

Occurs when a muscle is unable to produce optimal force because it is either too short or too stretched. This situation happens when a muscle is at its shortest length (contracted) across all the joints it spans.

Question 4

What is passive insufficiency

Answer 4

Occurs when a muscle is unable to lengthen enough to allow for full range of motion in the joint it spans because it is already stretched to its max length. This situation occurs when an antagonist muscle ( the muscle that performs the opposite action of the target muscle) is too stretched to allow full movement of the joint.

Question 5

what are the four sections (curves) of the spine

Answer 5

Cervical (C1-C7), thoracic (Th1-Th12), lumbar (L1-L5), sacral (sacrum and coccyx)

Question 6

What is a kyphotic spine

Answer 6

“Hunch back”, the thoracic curve of the spine is more eggadurated

Question 7

What is lordosis of the spine

Answer 7

When the lumbar curve of the spine is curves inwards, like sticking your bum out

Question 8

Features of the cervical region

Answer 8

Contain smaller more mobile vertebrae, two extra transverse foramina contain vertebral artery and vein.
The atlas (C1) support the head and forms the Atlanto-occipital joint which allows head movement.
The atlas also forms the atlanto - axial joint with the axis (C2).

Question 9

Features of the thoracic region

Answer 9

More restricted due to ribs, articulate with ribs.
Bigger than cervicals, increased weight bearing function

Question 10

Features of the lumbar region

Answer 10

Largest and strongest
Major role in weight bearing

Question 11

Features of the sacral region

Answer 11

Fused and transmit weight from body to pelvis and legs

Question 12

What are the muscles responsible for lumbar flexion

Answer 12

Rectus abdominis, external oblique, internal oblique, psoas major, iliacus
LOOK AND IDENTIFY

Question 13

What is the diaphragm

Answer 13

Flat muscle separating the thoracic cavity from the abdominal cavity

Question 14

How is the diaphragm used in breathing

Answer 14

Inhalation - it contracts, enlarging thoracic cavity which created suction that draws air into the lungs.
Diaphragm relaxes, air is exhaled by elastic recoil of the lungs and the tissues lining the thoracic cavity.

Question 15

What is structural postural deviation

Answer 15

Fixed in nature, generally due o bony deformities as a result of congenital or pathological processes

Question 16

What is functional postural deviation

Answer 16

Due to poor posture, pain, muscle imbalances and injury
Muscle imbalances - due to a group of tightened muscles which pull on the joints in the body and result in their opposing muscles becoming weak and lengthened

Question 17

What is upper cross syndrome

Answer 17

A pattern of muscle imbalances in the upper body that involves tightness in certain muscles and weakness in others. It is called a cross syndrome because the tight and weak muscles from a pattern that resembles an x when viewed from the side

Question 18

What is lower cross syndrome

Answer 18

A pattern of muscle imbalances in the lower body that involves tightness in certain muscles and weakness in others. The tight and weak muscles form a pattern that resembles an x when viewing from the side.

Question 19

What are the viscoelastic properties of biological materials

Answer 19

Elasticity, viscosity, stress-relaxation, creep, hysteresis

Question 20

As a viscoelastic property of biological materials - what is elasticity

Answer 20

Refers to the ability of a material to return to its original shape after a force is applied and then removed, biological tissues such as tendons and ligaments have elastic fibres

Question 21

As a viscoelastic property of biological materials - what is viscosity

Answer 21

Refers to a materials resistance to flow or deformation, in biological tissues viscosity is relates to the presence of fluids within the tissue such as in cartilage and synovial fluid in joints.
Viscous properties can provide damping and shock absorption during movement.

Question 22

As a viscoelastic property of biological materials - what is stress-relaxation

Answer 22

Occurs when a constant strain is applied to a material and the stress required to maintain that strain decreases over time, in biological tissues, this property can help reduce stress on the tissue when holding a stretch or load over an extended period

Question 23

As a viscoelastic property of biological materials - what is creep

Answer 23

The gradual increase in strain over time when a constant stress is applied, biological materials can exhibit creep, meaning they stretch further under sustained loads

Question 24

As a viscoelastic property of biological materials - what is hysteresis

Answer 24

Refers to the difference in energy absorbed and released by a material during loading and unloading, when biological tissues are loaded, there is often a lag between the two, and some energy is lost as heat.
This property can be observed when stretching a muscle and then releasing it, the muscle may not immediately return to its exact original length.

Question 25

What are the advantages of electromyography

Answer 25

Detailed muscle activity information - EMG provides a direct measure of muscle activity by recording the electrical signals generated during muscle contraction, offers insight into the timing, intensity and duration of muscle activation Diagnosis and assessment - EMG can help diagnose neuromuscular disorders such as muscular dystrophy, myopathy, and neuropathy, can assess nerve function and identify nerve damage or compression Research and clinical applications - EMG is used in research to study muscle function, movement patterns, and the effects of interventions such as exercise or therapy, clinically, EMG can guid treatment plans and monitor progress in rehab Biofeedback - EMG biofeedback is used in therapy to help patients learn to control specific muscles or muscle groups, aiding in recovery and rehab Portable and versatile - modern EMG devices can be portable and used in various settings, including clinical, research, and field environments

Question 26

What are the disadvantages of electromyography

Answer 26

Invasiveness - surface EMG is non-invasive, but intramuscular EMG can be invasive and cause discomfort to the patient signal interpretation - EMG signals can be complex and influenced by various factors, such as electrode placement, muscle fatigue, and external interference. Interpretation of EMG data requires expertise and understanding of the underlying biomechanics and physiology Limited scope - EMG measures muscle activity but does not directly provide info on muscle force, joint motion, or overall function. It may need to be combined with other assessments such as kinematic and kinetics for a more comprehensive analysis Skin impedance - for surface EMG, variations in skin impedance due to factors such as sweat, oil, and hair can affect the quality and reliability of the signal. Time consuming and costly

Question 27

Advantages of isokinetic dynamometry

Answer 27

Comprehensive information Isolate limb and stabilise adjacent segments Activate largest number of motor units and overload at their force output capacities during movement even at the relatively weaker joint angles Rehab application - patient can reduce the effort at this point yet exercise the joint system in the other non painful regions, furthermore the patient can simply stop in the mussel of an exercise without having to worry about controlling the load Concentric and eccentric contractions Adjust speed of movement Safe, minimal risk of injury

Question 28

Disadvantages of isokinetic dynamometry

Answer 28

Initial acceleration - Biodex (applies arbitrary braking torque to prevent velocity overshoot, other machines use different methods) Velocity significantly influences results Not sport specific - training effects not always transferable, sports rarely at constant velocity Max. Angular velocity quite low Cost implications and availability

Question 29

Explain how the muscle contracts using the contractile and elastic components

Answer 29

- as we generate tension, muscle becomes shorter, some tissue will be stretched, when tissue is stretched, elastic energy is stored within this tissue e.g. connective tissue - additional structures e.g. tendons, acts as a mean of transferring tension - transmits tension produced by contractile components - muscle inserted, muscle contracts, tendon inserted acts as a transmitter, transferring tension from the muscle

Question 30

What are the components of hills mechanical model and what does the model allow us to do

Answer 30

Contractile components - e.g. actin and myosin from cross bridges, generate active tension Elastic components - generate passive tension (resist lengthening, contribute passively to produce a higher muscular force) 1. Parallel elastic components - e.g. connective tissue, store elastic energy when stretched, released when muscle recoils 2. Series elastic components - e.g. tendons, transmit tension produced by contractile components to attachment of muscle Hills allows us to understand where the overall tension of a muscle comes from

Question 31

What are the two sources of overall tension and how do you calculate it

Answer 31

Total sum of tension = active x passive force Active - outcome of sliding filament theory Passive - tissue stretched and energy produced has the potential to return to the system

Question 32

What happens when the muscle is shortened and you try to generate force

Answer 32

Sliding filaments are overlapping - generates more force than lengthened muscle Around 50 percent tension

Question 33

What happens when muscle is lengthened and you try to generate force

Answer 33

Sliding filaments are far apart - generates less tension

Question 34

When does the muscle generate the maximum contractile force

Answer 34

At its resting length The rise and fall of active tension occurs due to the varying degrees of cross bridge overlap

Question 35

What is a first class lever

Answer 35

Fulcrum is between muscle force (effort) and resistance arm Draw out an example

Question 36

What is a second class lever

Answer 36

Resistance is between the fulcrum and the muscle force (effort) arm I.e the resistance is closer to the joint than the muscle force Draw out an example

Question 37

What is a third class lever

Answer 37

The force (effort) is between the fulcrum and the resistance I.e muscle force is closer to the joint than the resistance Draw out an example

Question 38

What is torque

Answer 38

Measure of the force that can cause an object to rotate around an axis or pivot point Forces that have the tendency to produce rotation

Question 39

What happens when the force is further away from the fulcrum

Answer 39

The further away it is, the longer the distance between the object and axis of rotation

Question 40

What is mechanical advantage of a lever and how do you calculate it

Answer 40

A measure of the force amplification achieved by using a tool, in this case a lever. The mechanical advantage of a lever is the effort arm divided by the resistance arm

Question 41

Are the effort arm and resistance arm always equal, explain cases where they are not

Answer 41

No, in cases where effort arm is more than the resistance arm, mechanical advantage is efficient, when ratio (MA) is more than 1 This means mechanical advantage is positive In cases where resistance arm is more than the effort arm, mechanical advantage is not very efficient (mostly what happens in the human body), when ratio (MA) is less than one The mechanical advantage is negative

Question 42

In the cases where MA is more than one, what does this mean

Answer 42

It is a lot easier to move an object and mechanical advantage is positive, where effort arm is longer than resistance arm

Question 43

In cases where MA is less than one, what does this mean

Answer 43

High speed, when effort lever is very short, we need to generate more force in order to move the segment, but segment can move very fast, MA is negative

Question 44

Explain the force velocity relationship in concentric actions (muscle shortening)

Answer 44

- the formation of cross bridges are effected when something happens really fast, less cross bridges will be formed = less tension created - the faster we perform a task, less tension created - as shortening velocity increases, cycling rate of cross bridges increases so fewer attached at any one time, thus decreasing force - velocity is increased at the expense of a decrease in force - maximum force generated at velocity =0 (large number of cross bridges attached) - maximum velocity contraction with lightest load - increased velocity of muscle contraction = increased cross bridge demand = fewer cross bridges to attach to = decrease in force Power (force x velocity) is critical - force becomes maximal in isometric contractions

Question 45

Explain the force velocity relationship in eccentric contractions (muscle lengthening)

Answer 45

- the formation of cross bridges are effected when something happens really fast, less cross bridges will be formed = less tension created - the faster we perform a task, less tension created - as velocity increases - the force we can generate also increases - eccentric action created = load by antagonist muscles, gravity or another external load - external load is more than the isometric strength applied - eccentric lengthening of muscle - increase velocity of lengthening increases = increase in force - muscle is stretching as it contracts - end abruptly when muscle can no longer control the movement of the load.