Here is one- although there are more:
Brachioradialis is a muscle of the forearm that acts to flex the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way of the brachioradialis tendon, and to the lateral supracondylar ridge of the humerus.
Mike O,
Please take the following with the largest grain of salt that you can find, as I am not the expert in this department.
It's my understanding that the brachioradialis aids only in flexion, not extension.
There are two muscles, the extensor digitorum and the extensor carpi ulnaris, that aid in the extending of the elbow. The extension of the elbow by these two muscles appears only to come after extension of the fingers and/or the wrist. At best, I think these muscles are subordinate to the actions of the triceps brachii and the anconeus.
Discounting the roles of the triceps brachii and the anconeus in the extending of the elbow requires intoxication.
Please take the following with the largest grain of salt that you can find, as I am not the expert in this department.
It's my understanding that the brachioradialis aids only in flexion, not extension.
There are two muscles, the extensor digitorum and the extensor carpi ulnaris, that aid in the extending of the elbow. The extension of the elbow by these two muscles appears only to come after extension of the fingers and/or the wrist. At best, I think these muscles are subordinate to the actions of the triceps brachii and the anconeus.
Discounting the roles of the triceps brachii and the anconeus in the extending of the elbow requires intoxication.
Mike wrote-: "The point is that some "forearm" muscles are able to flex the forearm and some forearm muscles are able to extend the forearm. Those are the muscles that cross the elbow joint."
Mike is correct and I applaud his questioning comments. I shouldn't have been so didactic by making a general overarching statement about forearm muscles that is only generally true, but not absolutely true. I therefore need to qualify my statements with a more detailed explanation, which is always a good thing, because it promotes a better (more accurate) understanding.
Theoretically, it can be said that any foreram muscle that has its origin (or part of its origin) above the elbow joint can assist in flexion or extension of the elbow joint depending on its position and muscle bulk - even though that forearm muscle may have another primary function (moving more distal joints).
I have therefore produced two photos.
The photos are too large to embed in this message, so I will provide links.
Take for example the aconeus muscle. It has its origin above the elbow joint and its insertion below the elbow joint. In that sense, it can be perceived to be an elbow extensor muscle. However, it is a comparatively tiny muscle relative to the triceps muscle and plays very little role in active elbow extension.
The same applies to the brachioradialis muscle. It has its origin above the elbow joint and its insertion near the wrist. It can definitely flex the elbow joint, but considering its relatively small bulk (compared to the biceps and brachialis muscles) and its far insertion point (which decreases leverage) it plays a far smaller role in elbow flexion that the upper arm muscles (biceps and brachialis muscles) which have great leverage because of their proximal forearm insertion points. Its main role is to produce a neutral forearm position when the forearm is extended in a non-neutral position (either supination or pronation) and the forearm is then flexed to a neutral position. It helps in rotating the forearm to a neutral position while assisting the biceps muscle in flexing the elbow.
Yodas Luke suggested that extensor digitorum and extensor carpi ulnaris may assist in elbow extension. I don't think that's correct and the photos show why I disagree - note that the extensor carpi ulnaris and extensor digitorum muscles actually arise from an origin below the elbow joint and its only their common extensor tendon that is attached to the humerus just above the elbow joint (at the lateral humeral epicondyle). They have very little leverage in extending the elbow joint - compared to the triceps muscle.
The extensor muscle that has its origin above the elbow joint is the long head of extensor carpi radialis, but its position and small bulk suggests that it has little role to play in elbow extension.
Look at the sheer size of the triceps muscle and the triceps tendon, and consider its advantageous point of insertion. You can then see why its the dominant muscle in elbow extension.
Mike wrote-: "The point is that some "forearm" muscles are able to flex the forearm and some forearm muscles are able to extend the forearm. Those are the muscles that cross the elbow joint."
Mike is correct and I applaud his questioning comments. I shouldn't have been so didactic by making a general overarching statement about forearm muscles that is only generally true, but not absolutely true. I therefore need to qualify my statements with a more detailed explanation, which is always a good thing, because it promotes a better (more accurate) understanding.
Theoretically, it can be said that any foreram muscle that has its origin (or part of its origin) above the elbow joint can assist in flexion or extension of the elbow joint depending on its position and muscle bulk - even though that forearm muscle may have another primary function (moving more distal joints).
I have therefore produced two photos.
The photos are too large to embed in this message, so I will provide links.
Take for example the aconeus muscle. It has its origin above the elbow joint and its insertion below the elbow joint. In that sense, it can be perceived to be an elbow extensor muscle. However, it is a comparatively tiny muscle relative to the triceps muscle and plays very little role in active elbow extension.
The same applies to the brachioradialis muscle. It has its origin above the elbow joint and its insertion near the wrist. It can definitely flex the elbow joint, but considering its relatively small bulk (compared to the biceps and brachialis muscles) and its far insertion point (which decreases leverage) it plays a far smaller role in elbow flexion that the upper arm muscles (biceps and brachialis muscles) which have great leverage because of their proximal forearm insertion points. Its main role is to produce a neutral forearm position when the forearm is extended in a non-neutral position (either supination or pronation) and the forearm is then flexed to a neutral position. It helps in rotating the forearm to a neutral position while assisting the biceps muscle in flexing the elbow.
Yodas Luke suggested that extensor digitorum and extensor carpi ulnaris may assist in elbow extension. I don't think that's correct and the photos show why I disagree - note that the extensor carpi ulnaris and extensor digitorum muscles actually arise from an origin below the elbow joint and its only their common extensor tendon that is attached to the humerus just above the elbow joint (at the lateral humeral epicondyle). They have very little leverage in extending the elbow joint - compared to the triceps muscle.
The extensor muscle that has its origin above the elbow joint is the long head of extensor carpi radialis, but its position and small bulk suggests that it has little role to play in elbow extension.
Look at the sheer size of the triceps muscle and the triceps tendon, and consider its advantageous point of insertion. You can then see why its the dominant muscle in elbow extension.
Jeff.
Well said Jeff- No problem from here. Although I kind of liked it when you finished with "If anyone disagrees with my opinion please comment"
__________________
Life Goal- Developing a new theory of movement based on Brain Science
Interests - Dabbling with insanity
Hobbies- Creating Quality
Don't know if you all have seen this.....should be interesting
Journalist and author of THE SEVENTH AT ST. ANDREWS, Scott Gummer’s HOMER KELLEY’S ODYSSEY, the untold story of Homer Kelley, a genius in engineering and an advocate for a scientifically perfect golf swing, showing the impact of his book The Golfing Machine on the game of golf, and relating the story of Ben Doyle, the teacher whom Kelley selected to translate and teach his methods to golfers.
Don't know if you all have seen this.....should be interesting
Journalist and author of THE SEVENTH AT ST. ANDREWS, Scott Gummer’s HOMER KELLEY’S ODYSSEY, the untold story of Homer Kelley, a genius in engineering and an advocate for a scientifically perfect golf swing, showing the impact of his book The Golfing Machine on the game of golf, and relating the story of Ben Doyle, the teacher whom Kelley selected to translate and teach his methods to golfers.
Please take the following with the largest grain of salt that you can find, as I am not the expert in this department.
It's my understanding that the brachioradialis aids only in flexion, not extension.
There are two muscles, the extensor digitorum and the extensor carpi ulnaris, that aid in the extending of the elbow. The extension of the elbow by these two muscles appears only to come after extension of the fingers and/or the wrist. At best, I think these muscles are subordinate to the actions of the triceps brachii and the anconeus.
Discounting the roles of the triceps brachii and the anconeus in the extending of the elbow requires intoxication.
Ted,
I was only addressing the middle portion of Jeff's post: "Forerarm muscles can only perform the following anatomical actions-:
1) Flex, extend, abduct or adduct the fingers and thumb.
2) Palmarflex or dorsiflex the wrist.
3) Radially deviate or ulnarly deviate the wrist.
4) Pronate or supinate the hand.
Forearm muscles cannot flex or extend the elbow joint because they are distal (peripheral) to the elbow joint.
Jeff."
Hopefully, that makes my post more relevant. The point is that some "forearm" muscles are able to flex the forearm and some forearm muscles are able to extend the forearm. Those are the muscles that cross the elbow joint. I wasn't posting to the degree of relevance or Bucket's drinking habits, all I was pointing out since Jeff asked was that his limited definition was not correct. Not all forearm muscles have tendon attachments that are distal to the elbow joint, as you correctly pointed out in your post with the addition of some extensor forearm muscles.
__________________
Life Goal- Developing a new theory of movement based on Brain Science
Interests - Dabbling with insanity
Hobbies- Creating Quality
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