A mystery of the elbow position in choku zuki 謎・直突きと肘の関係 (Part 2) 

Elbow injury during practicing choku-zuki

Elbow close up illustration

  • There are many karate-ka suffering from elbow injury during practicing choku-zuki. The elbow joint is formed of 3 bones come together to form the elbow joint (illustration right).

  • The top bone is the upper arm bone ( humerus )and in the base of humerus the trochlea which lie in the medial side & the capitulum which lie laterally.

  • Forearm formed of 2 bones (Radius & Ulna) to form the lower part of the joint.

  • The longest bone the Ulna it’s shape like a spanner with an upper jaw (olecranon process) and lower jaw (cronoid process).

  • The Ulna is attached to the upper arm bone and articulate with the trochlea of the humerus to allow the hinge like motion of the elbow.

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Elbow joint perform 2 types of motion numberBones Supine and Prone

1-The first type of motion

Flexion by the flexor muscles ( biceps, brachialis, brachioradialis, FL.of forearm ) & extension by extensor muscles (triceps, anconeus. M)

2- The second type of motion (illustration left)

  1. pronation by (pronator teres, pronator quadratus )

  2. supination by (biceps, supinator).

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*Elbow illustrations

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Elbow joint motion (illustrations right & below)

  • Elbow flexion from 0 to 145 °of flexion but functionally the angle should be from 30° to 130°.

  • Pronation averages around 80° and supination at 85° Both could reach to 90°. It is very important that you notice the pronation and supination are good when the elbow is flexed to 90°.

Screenshot_Joint Motion

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The carrying angle

  • This angle is found between humerus and Ulna. The trochlea of the humerus looks like an hour glass put on its side. The medial end of the trochlea has greater circumference than its lateral end.

  • Because of this difference in circumference between the two end of the trochlea as the Ulna swings round the trochlea from flexion to extension the Ulna becomes gradually forced laterally and does not lie in the line with the humerus. There is a difference of an angle about 15° which is called The carrying angle.

  • In pronation when the lower end of radius crosses over to the medial side of Ulna the carrying angle disappeared
  • Elbow illustrations 2

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Of course, many injury could happen to the elbow joint from other activities, for example :

  1. In the lateral side of elbow (tennis elbow injury )

  2. In the front side of elbow (distal biceps tendonitis and distal biceps tendon rupture).

  3. In the medial side of the elbow (golfers elbow or cubital tunnel syndrome or collateral ligament injury).

  4. In the posterior side of the elbow (Valgus extension overload or triceps tendonitis or elbow bursitis).

  5. Elbow problems typically occur where the tendon attaches to the bone.

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Tennis elbow:

  • It is caused by excessive strain on the muscles of the lateral side of the elbow which originated from the common extensor tendon especially when the wrist is extended. The problem area is mainly the extensor carpi radialis brevis muscle. The pain is usually slightly below the elbow attachments but the pain can radiate into the forearm.Tennis elbow joint illustration

  • So we will make a comparison between the karate-ka who practices choku-zuki with the direction of his elbow to the side and the karate-ka who keeps his elbow downward.

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First, the karate-ka who practices choku-zuki and the direction of his elbow to the side:

The following could be happen to him:

  • Tennis elbow injury may occur mainly due to flexion to extension of the wrist with sudden movement specially without proper warming up and stretching. In case of the direction of elbow to side during practicing choku-zuki, the injury may happen due to repeated stress and twisting the wrist resulting in a forceful contraction of wrist extensors.

  • There will be no complete pronation which means “the lower end of the radius will not crosses over the medial side of the ulna completely so that the carrying angle in the elbow joint will decrease only”.

  • The elbow joint will not lock completely.

  • The reaction power from the impact with the target will go directly to the elbow joint and the muscles around it.

  • There will be no maximum muscles contraction to the muscles of the forearm.

  • Due to repeated hyper-extension of elbow joint it may lead to another injury , {valgus extension overload }. Jamming of olecranon into fossa may cause bony spur on the tip of the olecranon.

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Now we will see karate- ka who practices choku-zuki and keeps the direction of his elbow downward:

  1. The position of elbow direction to downward will lead to stopping the hyperextension of elbow movement and results in decreasing the possibility of injury.

  2. There will be complete pronation to the forearm.

  3. When we rotate the fist medially to maximum 90° pronation while keeping the elbow downward and extended, the lower end of the radius crosses over to the medial side of Ulna, then the carrying angle disappears. {This will lock the elbow joint and make it more secure}.

  4. The reaction power from the impact with the target will retreat to the shoulder muscles that are stronger than the forearm muscles thus they can tolerate the impact.

  5. By making the direction of elbow downward and completing pronation, the muscles of forearm will be able to contract to the maximum.

  6. There will be no hyper-extension so the olecranon will not make collision with the olecranon fossa in the lower part from the back side of the humerus. This avoidance will prevent the injury {valgus extension overload}.

Karate do is life-time sport, so all karate-ka must be careful and avoid injuries. An injury coming from careless mistake will stop them from practicing karate. We, the medical staff always state that prevention is better than cure. We also recommend that before training, you will starts with good warm up and stretching to all the muscles in our body.

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Written by Dr.Ashraf Ragab

Note: This article will continue to cover the other karate related injuries in the future if the readers are interested.

Ragab portrait

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Some information about the author, Dr.Ashraf Ragab

Pharmacist B.Sc.Ph.Ph.Ch.

Faculty of pharmacy Cairo University

Date of graduation May 1983 with general grade “very good”

Sport injury specialist with excellent grade in 1/7/1998 from Olympic Academy of Athletic leaders

Karate examiner of Egyptian karate Federation from 11 years

Manager of karate section of Bank Ahly club

Lecturer at the Egyptian Karate Federation for :

Karate Athletic injuries & drug doping

Karate movement science

The highest ranking student degree at Olympic Academy of Athletic leaders with excellent grade in all branches .

 

1st position in national championship in August 1974 kumite group kumite Zamalek club under 16 years

1st position in national championship in 2007 kata

1st position in the professor’s championship in September 2000 Giza kata

 

Reference

*Illustrative upper limb El Rakkawy.

*Sports health the complete book of athletic injuries. William Southmayd & Marshall Hoffman.

*prof.Nabil Ebrahim MD chairman of department of orthopedic toledo university.

*Grant’s atlas of anatomy James E Anderson.

*Biomechanic of the elbow (Belhaven university, university sports medicine Mississippi health care )

*Anatomy and Biomechanics of the elbow joint (University of California) .

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