Write down the anatomy of Ulna. Also explain its features and muscle attachments?

-

 ULNA

The ulna is the medial bone of the forearm. It is homologous with the fibula of the lower limb. It has an upper end, a shaft and a lower end.


Features:
Upper End:
The upper end presents the olecranon and coracoid processes, and the trochlear and radial notches.
  1. The olecranon process projects upwards from the shaft. It has superior, anterior, posterior, medial and lateral surfaces.
  • The anterior surface is articular, it forms the upper part of the trochlear notch.
  • The posterior surface forms a triangular sub cutaneous area which is separated from the skin by a bursae.
  • The medial surface is continuous inferiorly with the medial surface of the shaft.
  • The lateral surface is smooth, continues as posterior surface of shaft.
  • The superior surface in its posterior part shows a roughened area.
2. The Coracoid process projects forwards from the shaft just below the olecranon and has four surfaces.
  • The superior surface forms the lower part of the trochlear notch.
  • The anterior surface is triangular and rough. Its lower corner forms the ulnar tuberosity.
  • The upper part of the lateral surface is marked by the radial notch for the head of the radius.
  • The medial surface is continuous with the medial surface of the shaft.
3. The Trochlear notch forms an articular surface that articulates with the trochlea of the humerus to form elbow joint.
4. The radial notch articulates with the head of the radius to form the superior radioulnar joint.
Shaft:
The shaft has three borders and three surfaces.
Borders:
  1. The Lateral border is the sharpest in its middle two-fourths. Inferiorly it can b traced to the lateral side of the head.
  2. The Anterior border is thick and rounded. It begins above on the medial side of the ulnar tuberosity, and terminates at the medial side of the styloid process.
  3. The posterior border is subcutaneous. It begins, above at the apex of the triangular subcutaneous area at the back of the olecranon and terminates at the base of the styloid process.
Surfaces:
  1. The Anterior surface lies between the anterior and interosseous border. A nutrient foramen is seen on the upper part of this surface. 
  2. The Medial surface lies between the anterior and posterior borders.
  3. The Posterior surface lies between the posterior and interosseous border. It is subdivided into three areas by two lines ( oblique line and vertical line ).

Lower End:
The lower end is made up of head and the styloid process. The head articulates with the ulnar notch of the radius to form inferior radioulnar joint. The styloid process projects downwards from posteromedial side of lower end of the ulna. Between head and styloid process, there is a groove for the tendon of extensor carpi ulnaris.
Muscle Attachments:
  • The Triceps Brachii is inserted into the rough posterior part of the superior surface of the olecranon.
  • The brachialis is inserted into the anterior surface of the coronoid process including tuberosity of the ulna.
  • The Supinator arises from the supinator crest and from the triangular area in front of crest.
  • The pronator quadratus takes origin from the oblique ridge on the lower part of the anterior surface. 
  • The Flexor carpi ulnaris arises from the medial side of the olecranon process.
  • The Extensor carpi ulnaris arises from the posterior  border.
  • The ulnar collateral ligament of the wrist is attached to the styloid process.
Clinical Anatomy:
  • Madelung's deformity is dorsal subluxation of the lower end of the ulna, due to retarded growth of the lower end of the radius.
  • Fracture of the olecranon is common and is caused by a fall on the point of the elbow. 
  • Dislocation of elbow is produced by a fall on the outstretched hand with the elbow slightly flexed.

References:
BD Chaurasia's Human Anatomy Of Upper Limb
Chief Editor:
Krishna Garg, Pragati Sheel Mittal, Mrudula Chandrupatia

About Author:
Tayyba Saleem ( PT )
Doctor Of Physical Therapy. 

Comments

Post a Comment

Popular posts from this blog

Write a note on Faradic current? Explain its physiological effects and indications.

-
  FARADIC CURRENT: A Faradic current is a short-duration interrupted direct current with a pulse duration of 0.1-1 ms and a frequency of 50-100 Hz. Modified Faradic Currents: Modified faradic currents include the surging of current. they produce a near-normal tetanic like contractions and relaxation. The current is surged , so that intensity of impulses increases gradually. The circuit can b modified by giving surges of different durations and frequencies. Various forms of surges may b available, which are trapezoidal, triangular and saw-tooth impulses. Physiological Effects : The physiological effects of faradic currents are as follows: 1. Stimulation Of Sensory nerves:                                                           When a current of faradic type is applied to the body, a mild prickling sensation is felt. This is due to the stimulation of sensory nerves. The sensory stimulation causes a reflex vasodilation of the superficial blood vessels, thats why slight reddening of ski
Read more

Write down the translatoric joint play movements. Explain normal grades of translatoric movement?

-
Image
Translatoric Joint Play Movements: The translatoric joint play movements used in the OMT Kaltenborn-Evjenth concept are Traction, Compression and gliding. Traction: Tra ction ( separation ) is a linear translatoric joint play movement at a right angle to and away from the treatment plan.  Compression: Compression ( approximation ) is a linear translatoric movement at a right angle to and toward the treatment plane.   Compression presses the joint surfaces together. It is usefu l to differentiate between articular and extra-articular lesions. Gliding: Translatoric gliding is a joint play movement parallel to the treatment plane.  Translatoric gliding is possible over a short distance in all joints because curved joint surfaces are not perfectly congurent.  Grade 1 traction is always performed simultaneously with a translatoric gliding movement. Normal Grades Of Translatoric Movement: Normal grades of translatoric movement gives Pain-relief mobilization, Relaxation mobilization and then
Read more

Define Range of motion. Write down the types and normal Ranges of motion.

-
  Range OF Motion: It is defined as, the full motion which is possible to perform is called ROM.  It is a basic technique used for the examination of movement and for initiating movement into a program of therapeutic intervention.  Active Insufficiency: When a two-joint muscles functioning at elbow is the biceps brachii muscle, if it contracts and moves the elbow into flexion and the forearm into supination while simultaneously moving the shoulder into flexion, it shortens to a point. Passive Insufficiency: The muscle is lengthened full range by extending the elbow, pronating the forearm, and simultaneously extending the shoulder. Types Of ROM Exercises: Passive ROM Active ROM Active-Assistive ROM. Passive ROM: Passive ROM is movement of a segment within the unrestricted ROM that is produced entirely by an external force, there is little to no voluntary muscle contraction.  The external force may be give with a gravity, machine and other individual.  Indication for PROM: When there i
Read more