What is humeral retroversion?
Humeral retroversion is generally defined as the angular difference between the orientation of the proximal humeral head and the axis of the elbow at the distal humerus. The retroversion angle of the humeral head has a wide range of variability, from –6° to 60°.
What is the anatomic retroversion of the humeral head?
Humeral head retroversion was defined as the angle between the humeral head axis and both the elbow epicondylar axis and the elbow tangent axis (Fig. 3B).
What is the angle of inclination of humerus?
Humerus •The head faces medially, superiorly, and posteriorly with regard to the shaft of the humerus. ANGLES: 1. Angle of inclination=130-150 degrees 2.
What is angle of humeral torsion?
Angle of humeral torsion is defined as the angle formed between the proximal and distal articular axis of the humerus. This angle is measured at the intersection of two lines: one that evenly bisects the articular surface of the humeral head proximally and the second being the transepicondylar line distally [1,2].
What is retroversion of the arm?
The humeral torsion or humeral head retroversion (UHR) is an anatomical feature that exists only in monkeys and hu-mans; it is defined, in anatomy, as the spiral movement of this bone, stabilizing at the end of growth with the closure of the humerus proximal epiphyseal line.3 4 It is known that UHR is characterized by …
What is the average humeral Retroversion?
The average angle for humeral head retroversion was 33 degrees on the dominant side and 29 degrees for the nondominant side.
What is glenoid Retroversion?
Glenoid retroversion is the abnormal posterior angulation of the articular surface of the glenoid of the scapula and is of importance as it predisposes to posterior glenohumeral instability and tears of the posterior labrum.
What is inclination of the shoulder?
Glenoid inclination, as described by Hughes et al20 and Maurer et al,27 is commonly thought to be the angle between the floor of the supraspinatus fossa and the glenoid fossa line: the β angle.
What is the normal humeral angle of torsion?
The true value of the angle of the humeral torsion is obtained by subtracting 90° from the obtuse angle, while the angle of retroversion is a complementary angle of torsion. This study finds the average angle of humeral torsion to be 56.61±9.57 and retroversion to be 33.39±9.52°.
What is twist angle?
Angle of twist: For a shaft under torsional loading, the angle through which fixed end of a shaft rotates with respect to the free end is called the angle of twist. As the torque is increased, the outer region of the shaft behaves like a plastic material while the inner core is still linear elastic.
What is normal glenoid version?
Normal glenoid version in most studies has been reported close to 0°, sometimes with slight anteversion but more often slight retroversion with values typically less than 10° in either direction [1–8].
How is glenoid Retroversion measured?
To determine the glenoid version angle, a line is drawn between the anterior and posterior margins of the glenoid (Fig 3). If the posterior margin of the glenoid is medial to the line of neutral version, then the glenoid cavity is retroverted.
What is the retroversion of the humeral head?
Retroversion of the humeral head and the range of motion of the shoulder joint in both the frontal and the scapular plane have been studied in 100 shoulder joints in 50 healthy subjects, 25 men and 25 women. The average angle for humeral head retroversion was 33 degrees on the dominant side and 29 degrees for the nondominant side.
What is the ratio of scapular and humeral contributions?
Also during scapular plane rotation from 25° to 125°, children showed greater upward rotation than adults. Ratios are often described as nonlinear indicating changing ratios during ROM. The 2 to 1 ratio substantially varies in scapular and humeral contributions at different points in the ROM and among individuals.
How many degrees does the humerus have to be retroverted?
So the humerus must be retroverted 15 degrees. What if the person is tight, or total motion is not symmetrical, but rather the dominant arm has less than the 180 degrees that the nondominant arm exhibits? Then measuring gets a little trickier. A simple measurement technique is to measure the amount of rotation the arm sits in when relaxed.
When does the normal position of the scapula cause a disfunction?
Introduction. This interaction is important for the optimal function of the shoulder. When there is a change ment of the normal position of the scapula(describe) relative to the humerus, can this can cause a disfunction of the scapulohumeral rhythm. The change of the normal position is also called scapular dyskinesia.