Elbow Flashcards
The (shoulder/elbow) provides stability and mobility for the hand, allows manipulation in the environment, and controls the position of our hand in space.
elbow
The elbow allows the (upper extremity/lower extremity) to be shortened and lengthened
upper extremity
The humerus and ulna are going to be a part of the (active/passive) subsystem when thinking of the elbow.
passive
Three things that (decrease/increase) stability at the humerus include its’ anterior inclination, shape of the trochlea, & the medial distal projection.
increase
The bony architecture at the ulna favours (extension/flexion) and this is the predominant motion here. In extension you are going to run out of room due to bony articulations. You run out of space when flexing the elbow, not because the joint can’t go anymore, but because of soft tissue approximations that get in the way.
flexion
The shape of the trochlea is going to guide (stability/mobility). The trochlea groove is going to make it so the pieces fit together and because of that groove and the reciprocal ridge that goes inside that groove, you are going to get a lot of bony stability at the elbow joint. As the groove takes up that space there is a lot of congruency through that range of motion.
stability
The medial-distal projection of the ____ is going to produce a carrying angle.
trochlea
Because of the interactions of your ulna with the “distal” part of the humerus, it offsets you a bit to the point if you hold your arms to the side it is not like my forearm goes straight down. We call this a _____ _____ because if I am carrying something in my hand I don’t want my arm to bump into my pelvis. We all have variations of how much of this we have from person to person.
carrying angle
Men have a carrying angle of _ to _ degrees and women have a carrying angle of _ to _ degrees.
5 to 10; 10 to 15
The distal portion of the limb moving away from the body is a (varus/valgus) alignment.
valgus
Consequences of having excess valgus or an excess carrying angle would be increased compressive forces on the (lateral/medial) surface with increased tension on the (lateral/medial) soft tissue structures. So the (UCL/RCL) would be under more tension.
lateral; medial; UCL
The distal portion of the limb moving towards the body is a (varus/valgus) alignment.
varus
(Low/high) rates of force and (low/high) external torques coming through a poor alignment is when you will see injuries with regard to the varus and valgus alignments. It is too much for the internal torque to overcome.
high; high
The name of the force that the ulnar collateral ligament would resist would be a (varus/valgus) force. If I wanted to apply a valgus force I would push the elbow medially and pull the forearm laterally, so now I am creating a tensile force on the inside medial structures by taking the distal portion and moving it away from its midline to recreate a valgus alignment and pushing him into more valgus alignment so now he is experiencing a valgus force on the medial side and that is what the UCL will resist.
valgus
The medial collateral ligament and lateral collateral ligament (provide/ do not provide) resistance to distraction of the ulna from the humerus
provide
The lateral collateral ligament will resist the (valgus/varus) force at the elbow.
varus
What are the three joints of the elbow?
The ulnohumeral, radiohumeral, & the proximal radioulnar joint.
When talking about the elbow, the capsule surrounds (all three/two) joints of the elbow, the capsule is (dense/loose) anterior and posterior and it is reinforced by a lot of muscle that pass by it.
all three; loose
Most of the fibers of the anterior band of the UCL are taught at full (flexion/extension)
extension
Most of the fibers of the posterior band of the UCL are taught at full (flexion/extension).
flexion
The (anterior/transverse) band of the UCL goes from one side of the ulna to the other side and prevents the humerus from coming toward our body and holds the distal humerus in its’ position.
transverse
The anterior band, posterior band, and transverse band of the UCL work together to provide resistance against (valgus/varus) force throughout the full motion.
Valgus
What does the annular ligament wrap around?
The head of the radius
The annular ligament will primarily resist (valgus/varus) forces
varus
The UCL is most taught in (extension/flexion)
flexion
The LCL is most taught in (extension/flexion)
flexion
If I wanted to apply a varus force I would push the elbow (laterally/medially) and pull the forearm (laterally/medially) . That would be a varus force to the outside portion of the elbow and that would put stress on the (LCL/MCL).
laterally; medially; LCL
What was most responsible for the resistance to distraction in full extension and what was the percent?
Anterior capsule; 70%
The (posterior/anterior) capsule is taught in extension so it is going to be much more easily responsible for preventing distractions.
anterior
What was most responsible for the resistance to distraction in full flexion and what was the percent?
The MCL; 78%
The MCL’s unique property is tension sharing or tension transference. So one portion of the MCL is more on slack during flexion and another portion is more tight so that is the key. The MCL has that interesting property where the fibers can really makeup for each other at (different/the same) points of the ROM.
different
What is the major reason why there is resistance to varus structures in extension? At what % is it responsible for in terms of the resistance?
Articulations; 55%
What is the major reason why there is resistance to varus structures in flexion? At what % is it responsible for in terms of the resistance?
Articulations; 75%
If we naturally have this inclination here it is almost as if you are already starting in a compressed position laterally, so there is going to be less ability to move into that position. The articulation is really important and it is stopping that (valgus/varus) force In flexion and extension.
varus
What contributes to the resistance of valgus forces in extension from least to greatest and what are their percents?
The MCL (31%), the articulation (31%), and the anterior capsule (38%)
What is the major reason why there is resistance to valgus structures in flexion? At what % is it responsible for in terms of the resistance?
The MCL (54%)
If I am in full (extension/flexion) and I have a positive valgus stress test in this position a lot of times it really means that there is a serious injury because it is not just the ligament that is affected, it is probably a bone, it is very lax.
extension
When you develop your test, you are going to have to figure out what is the ideal way to test for the UCL. Would it be in full extension? No, it is not going to be in full extension because you could get a false negative and say its not really laxed at all, but they still have a UCL injury and start to bend it 30 degrees and now you feel laxity and/or pain. You are getting more into this flexed position where the (LCL/MCL) has a greater percent of responsibility for stopping the valgus force.
MCL
The anterior band from the MCL is most taught during full (flexion/extension) but it does not have the most percentage of responsibility for stabilizing the valgus force.
extension
The radioulnar joint (is not/is) as stable as the ulnohumeral joint.
is not
The radioulnar joint (does not have/ has) a lot more freedom of movement within this annular ligament.
has
What movements occur at the radioulnar joint?
Pronation and supination
What are three things that would be a restraint to supination at the radioulnar joint?
The TFCC, interosseous membrane, & the palmar side of the distal radioulnar joint (PRUJ) capsular ligaments
What are two things that would be a passive restraint to pronation?
The TFCC and the dorsal capsular ligaments
If I push somebody’s shoulder into extension, the shoulder flexors are stopping me from moving into that position. So if i supinate, anything that does ____ is going to be a passive restraint to supination.
pronation
The ____ membrane is a membrane that connects the radius to the ulna.
interosseous
Overall, the interosseous membrane has fibers that run in multiple different directions but there is an overriding theme or a predominant number of fibers that run in a (distal-medial/proximal-lateral) orientation. What this prevents is a separation of the radius and the ulna. If most of the fibers are running in a (distal-medial/proximal-lateral) direction it is going to keep the radius and the ulna together and it will stop the radius from getting driven (inferiorly/superiorly).
distal-medial; distal-medial; superiorly
The radius is larger (proximally/distally) than it is (proximally/distally), so it has more surface area (proximally/distally). If the force that gets absorbed distally and this person lands and compresses the joint, we know that if the force is dispersed over a bigger surface area you are much better off in terms of not getting hurt. So if you absorb a large force distally at the radius and then it gets transferred to a small surface area up stream, you could theoretically have an injury more proximally. So instead what mother nature gave us was this interosseous membrane so as this force, which is very large at the distal radius and small on the distal ulna comes through, it can dissipate some of that force through the interosseous membrane and kind of give it a little bit more to the ulna because the ulna is reversed and it has a small surface area distally and a larger surface area proximally. So now because of that you can disperse the force evenly as you move your way up and that transition happens in the interosseous membrane is picking up some of the forces and getting it to become a little bit more even as it crosses the elbow joint.
distally; proximally; distally
Most of the injury at the wrist happens at the distal (ulna/radius), it is the primary load bearing portion of the wrist.
radius
Things that originate at the elbow are prime movers of the (shoulder/wrist).
wrist
If you start on the humerus and cross through the forearm to the wrist and start on the shoulder and cross the humerus and the elbow joint and attach to the forearm, that is making a lot of possibilities as far as length tension goes. So now I can manipulate my shoulder and elbow and all of that interplays out in itself, so my wrist will be at a different strength depending on what position I put my (elbow/shoulder) in and my elbow will be at a different level of strength depending on where I put my (elbow/shoulder) .
elbow; shoulder
The (brachialis/brachioradialis) is able to work in elbow flexion no matter what position the forearm is in.
brachialis
The (brachialis/brachioradialis) can maximally flex the elbow when in a mid pronated position. The mechanical advantage is the greatest in this position.
brachioradialis
In scenario B, because I am now shortening the biceps and I take a second to flex it, I have now covered 7cm (from 30 cm to 23cm) and it is moving at 7cm/s. I
In scenario C, because I am not shortening the biceps as much and I do that same contraction and instead I cover 25cm at 5cm/s. The speed of contraction in scenario B is faster than the speed of contraction in scenario C and according to the force/velocity curve if the contraction occurs at a slower pace you generate (less/more) force.
more
. If someone does not have the force creating capabilities with their elbow flexors you might have to change the (position/speed) in which they do their training to be able to produce more force and achieve the same goal.
position
If you are working with someone and you are saying you really want them to strengthen their elbow flexors and they might only have a 5lb weight with them. This is about the internal force that is generated. So if this person had a 5lb dumbbell and could not lift it. If you take that person and put them in position C where their arm is (further from/ closer to) their body they will be able to generate more internal force to be able to lift that weight.
closer to
If a muscle generates more force it can do more work. If you are performing a slower concentric contraction you will be able to produce (less/more) force than a faster concentric contraction and that relates back to the force/velocity curve.
more
In a pushup position, as the individual is going down into elbow flexion the triceps are working (eccentrically/concentrically) and providing stability through the elbow joint during the movement.
eccentrically
The elbow joint really provides more stability in (open/closed) kinetic chain activities.
closed
The interesting thing about the triceps is that its’ moment arm is greatest near (full extension/ 90 degrees) and that has to do with the anatomy of the ulna and olecranon and where it is positioned during full extension. There is greater strength/force production of the triceps at (full extension/90 degrees) and that has to do with the idea of optimal length tension.
full extension; 90 degrees
The (biceps brachii/supinator) muscle is the primary mover when It comes to supination.
supinator
If I am putting together a piece of equipment and it is literally just turning in a screw driver (supination) or doing something that does not require a lot of force generation, the (supinator/biceps brachii) is the muscle that is primarily working. As soon as you start doing activities with heavier loads and you really have to crank on that screw to tighten it or loosen it (supination) the (supinator/biceps brachii) is going to take over and kick in for supination.
supinator; biceps brachii
When you perform supination with a heavy load the triceps muscle becomes very active. If I am really heavily screwing in a part and it is not going in and I am really working and creating a lot of force (supination) the biceps brachii is working. We also know that the biceps are an elbow flexor so if the biceps is contracting heavily and my main goal is to use the biceps to supinate, in order to avoid the elbow flexing, the triceps have to kick in to really stabilize the arm to prevent the elbow from (flexing/extending).
flexing
In pronation, the (pronator teres/pronator quadratus) is used for power.
pronator teres
The (pronator teres/pronator quadratus) has a dual role in pronation and stabilizing the distal radial ulnar joint.
pronator quadratus
The elbow joint isn’t quite perfectly in the (frontal/sagittal) plane and there is the medial projection of the humerus that throws things off and creates this carrying angle. So we will actually be looking at an inferolateral/inferomedial axis of rotation in flexion/extension, but for all intensive purposes we are still going to say flexion/extension of the elbow is in a sagittal plane with a ML axis, just know that it is a bit off.
frontal
The functional range of flexion/extension at the elbow is between _ - _ degrees and this is the amount of motion that you can have where you can get most of the things in your life done without honestly much difficulty.
30-130
The elbow is typically a joint that tends to get very (stiff/flexible). Some of those rules that you will learn during PT school about immobilizing a joint for 6 weeks for bony injuries and things like that.. A lot of that does not apply with the elbow. If you immobilize the elbow for six weeks the bone will be healed but you will not be able to use the arm all that well so you have to be a little more aggressive with it.
stiff
In the humero-ulnar joint the ulna is (concave/convex) and the humerus is (concave/convex), and in flexion/extension the rolls and slides will be in the (same/different) direction.
concave; convex; same
In the humeroradial joint, the radius is (concave/convex) and the humerus is (concave/convex) so the rolls and slides will be in the (different/same) direction during flexion/extension.
concave; convex; same
During flexion of the elbow, the anterior capsule will be (slacked/tensioned) and the posterior capsule will be on (slacked/tensioned).
slacked; tensioned
During the extension of the elbow, the anterior capsule is going to stretch out and be (taught/slacked). The posterior capsule will be (taught/slacked)
taught; slacked
In pronation and supination of the forearm, the axis of rotation is going from the radial head to the ulnar head (the dotted line in this picture). When we describe pronation and supination, the thumb is always sticking with the radius. So as I pronate, I am visualizing the (radius/ulna) distally rolling over the (radius/ulna) head.
radius; ulna
The functional range of motion for pronation and supination (starting from the neutral position) is _ degrees in either direction to be able to turn a dorrknob or use tools or ADLS.
50
The arthrokinematics of the proximal radioulnar joint moving from supination to pronation is __. Within the annular ligament the radial head is spinning but it is actually happening at the humeroradial joint.
a spin
In the arthrokinematics of the distal radioulnar joint, the radius is (concave/convex) and the ulna is (concave/convex).
concave; convex
The arthrokinematics of the distal radioulnar joint moving from supination to pronation is the concave radius moving on a convex ulna. You are going to consider the ulna as being fixed. So if I am supinated and I go into pronation, I have the concave radius rolling and sliding on a convex ulna (anteriorly/posteriorly), but to go back to supination it is rolling and sliding (anteriorly/posteriorly).
anteriorly/posteriorly
If I am throwing a baseball at a high rate of speed the (medial/lateral) aspect of my elbow will be under tensile stress.
medial
When the elbow is (locked/unlocked) it does not have as much bony and capsule support. So it is not as tight, but it does not have as much help in this position. So you are going and throwing at a high rate of torque and now if you do not have enough shoulder motion you are now creating more torque for your elbow joint and you will get more injuries to your elbow. When you have excessive tensile forces medially you will create more laxity, more laxity, more laxity, which equates to an increased neutral zone because you have more laxity and it took you further to engage the ligament and that principle holds up for all ligaments, not just spinal ligaments. So you have an increased neutral zone so it takes longer for it to get tensioned and you are creating more velocity behind it and now its getting fully tight at the last second and then eventually it can tear.
unlocked
The way you test the UCL ligament is to unlock the elbow to 30 degrees and create a (varus/valgus) force to stress the UCL.
valgus
A positive test for a UCL tear would be what?
A lot of pain or discomfort
Creation of a lot of torque through the system will cause the forearm and the humerus to compress together and is usually in young athletes who are really really good and have good biomechanics to create the amount of torque. If you have really good biomechanics and you are harnessing every ounce of force from your toes all the way to your finger tips, you can generate enough (tension/compression) to move your joint where you get a lesion in the articular cartilage. The lesion would be (medially/laterally) because we already know that the tensile forces would be on the (medial/lateral) side, so the compressive forces have to be on the other side. So these lesions usually happen on the (medial/lateral) side on the radial head. It is more common in youths than adults because in adults the joint is fully mature and it will handle the forces.
compression; laterally; medial; lateral
In young people the radial head is not fully developed you can pull away from someone (think of someone trying to hold you and you are trying to get away) and have the force going another way and now the radial head pulls through the annular ligament, so it pulls out of the annular ligament so the annular ligament is superior to the radial head and is occupying the space between the radial head and the humerus. If the radial head was bigger (a fully formed adult) the radial head (could not/could) pull through the annular ligament.
could not
