Asian Journal of Medical Sciences 4(5): 174-178, 2012
ISSN: 2040-8773
© Maxwell Scientific Organization, 2012
Submitted: August 09, 2012
Accepted: September 08, 2012
Published: October 25, 2012
Determination of Angles of Torsion and Retroversion of the Humerus of
Male and Female Skeleton Specimens in Uganda
1
S.S. Dare, 3M.G. Masilili, 1G. Okumu, 1Y.G. Mohammed, 1S. Abba and 2A.O. Okpanachi
1
Department of Human Anatomy,
2
Department of Human Physiology, Faculty of Biomedical Sciences, Kampala
International University, Uganda
3
Department of Human Anatomy, School of Health Sciences, Makarere University, Uganda
Abstract: Several studies have been done on the measurement of angles of humeral torsion and retroversion in
different parts of the world but no records to show for any done in Uganda. In this study we aimed to determine the
angles of humeral torsion and retroversion of adult skeletons in Uganda and to compare the observation in this study
with the findings of other workers in different races and discussing our finding in light of literatures. Measurement
of the angles of humeral torsion and retroversion of adult skeletons was done at the Galloway Osteological
Collection (Museum) Mulago, Uganda, to determine the angles of torsion and retroversion of the humerus in male
and female specimen. 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°. The angle of torsion of the right and left
humeri, been 54.67±9.62 and 58.55±9.52 respectively, while retroversion angle is 35.33±9.62 on the right and
31.45±9.52 on the left. Therefore there is a greater torsion angle on left side than on the right side and retroversion is
less on the left side than on the right side. There was a significant difference between the mean value of the torsion
angle of the right and left humeri of the same skeleton, therefore confirming that there is a difference between the
angle of torsion and retroversion on the two sides (right and left) in a particular person.
Keywords: Glenohumeral, humeri, museum, osteological, torsiometer, transcondylar
humeral head retroversion among individuals
undergoing operation and the ways in which this
parameter might be manipulated to surgical advantage.
In comparison to other mammals, man’s humerus
has undergone a twist about its long axis so that the
proximal end faces more medially and posterior
(Martin, 1933) and with this variation is termed a ‘retro
torsion’. A humerus is more ‘antedated’ if the head is
facing away from a direction that is in a more anterior
and lateral orientation. Broadly speaking the definition
of this twist is the angle between the longitudinal axes
of the particular surfaces of each end of the bone. In the
majority of mammals these lines are perpendicular to
one another, but in the higher primates this axis has
rotated so that the angle is greater than 90°. Precise
definitions and descriptions of humeral torsion vary
between anatomists, anthropologists and clinicians
(Whiteley, 2009). Recent biomechanical studies suggest
that humeral retroversion may have a significant
bearing on shoulder function and shoulder injuries
(Gjerdrum et al., 2003).
This study aimed to determine the angles of
humeral torsion and retroversion of adult skeletons at
the Galloway Osteological Collection (Museum) of
Department of Anatomy, College of Health Sciences at
INTRODUCTION
Humeral torsion and retroversion angle refer to the
angles created by the transcondylar axis of the distal
humerus and a line that bisects the humeral head
(Gjerdrum et al., 2003). Torsion is defined as a state of
longitudinal twisting or spiraling of shaft of a long bone
and can be measured as the difference between joint
axis of proximal and distal ends of the bones (Shah
et al., 2006).
Measurement of humeral torsion is important
because it enables clinicians to make justifiable
assumptions as well as make inferences about the
position of the glen humeral joint in relation to shoulder
range of motion and particular to shoulder rotational
range of motion. Therefore data generated from the
study of the angles or degree of humeral torsion and
retroversion may give clinicians a clearer understanding
of how the structure of the bone, muscle and ligaments
influence or limits the shoulder range of motion.
A good knowledge of the range of values of the
torsion and retroversion angles in skeleton specimen
within this population may assist clinicians in
estimating this angle in living subjects. Also it is of
clinical importance to understand the variations in
Corresponding Author: S.S. Dare, Department of Human Anatomy, Faculty of Biomedical Sciences, Kampala International
University, Uganda
174
A
Asian
J. Med. Sci.,
S 4(5): 174--178, 2012
Makerere University Uganda
U
and to
t compare the
t
observationn in this stud
dy with the findings
fi
of othher
workers inn different racces and discuussed in light of
literatures.
S AND METH
HODS
MATERIALS
Study arrea: This stu
udy was donne at Gallow
way
Osteologiccal Collection
n, Departmentt of Anatom
my,
School of Biomedicall Sciences and
a
Maker ere
e
University College of Health
H
Sciencees at Maker ere
e
University in 2011. It consists of over
o
232 sets of
skeletons both
b
female an
nd male and of
o different agges
and geograaphical origin.
Study deesign: This study is a cross-sectionnal
descriptivee and quaantitative sttudy involviing
measuremeents. It was carried
c
out byy collecting daata
using data form to docum
ment measurem
ment of the anggle
of torsion and
a retroversio
on of the humerri.
Fig. 2: P
Photo 2 showinng a pin fixed allong the referennce line
e
employed
for the
t
lower end of the Humeruss (Shah
e al., 2006)
et
Selection criteria:
c
Inclusion criteria:
m numbers
 Boness with museum
 Boness which are nott broken
 Boness with biograph
hic data i.e., oriigin and gendeer
Exclusion criteria: h
bones
 Non human
Data colleection tool/insstruments: A torsiometer was
w
used to meeasure the ang
gles of torsion and retroversiion
in degreess. Using a meethod describeed by Krahl and
a
Evans (19945), the mech
hanical axis of
o the head was
w
taken as thhe line joining the
t two points namely centerr of
the particuular surface of head
h
where traansverse diameeter
of particullar surface is maximum annd at the greaater
tuberosity approximately between thhe insertions of
p
supraspinaatus and of thee infraspinatuss muscles. A pin
was stuck with plastic in
i along the liine of these tw
wo
points (Figg. 1). For thee distal end axxis, a point was
w
marked onn the anterior su
urface of capittulum along the
t
center of its
i vertical diameter and a second
s
point was
w
Fig. 3: P
Photo 2 showinng the measurem
ment of the anggles of
t
torsion
and retrooversion
markedd on the trochhlea and a pinn was stuckedd with
plastic in along the linne of these twoo points (Fig. 2).
2 The
f
by thee crossing of these two refe
ference
angle formed
lines was
w then measuured with the Torsiometer
T
annd this
angle is the torsion angle (Figg. 3). The orriginal
descripption of Krahl’ss torsiometer iss shown in Fig. 4.
Data analysis: Data
D
collecteed was anaalyzed
u of SPSS (Scientific Packaage for
scientiffically by the use
Social Sciences) verssion 17. All daata was expresssed as
MeanSEM. The data was annalyzed by Cross
Tabulattion and Pairred Sample t-test
t
with muultiple
comparrisons which were
w
tabulatedd for discussioon into
tables. A p-value of <0.05 is consiidered as significant
d
collectedd was
and coorrelations beetween the data
determiined using Peearson’s correllation. The anngle of
torsion and retroversiion of the rightt and left humeeri was
i the same skkeleton specimeen and
comparred generally, in
betweeen genders.
TS AND DISCU
USSION
RESULT
Fig. 1: Photto 1 showing a pin fixed alongg the reference line
empployed for the upper end of the
t Humerus (Shhah
et all., 2006)
m is 54.54±0.69 on
Thhe mean of torssion angle in male
the righht and 58.71±00.66 on the lefft while in fem
male its
175 Asian J. Med. Sci., 4(5): 174-178, 2012
55.47±1.59 on the right and 57.56±1.96 on the left. The
mean angle of retroversion in male is 35.46±0.69 on the
right and 31.29±0.66 while in female its 34.53±1.59 on
the right and 32.44±1.96. Generally, the mean angle of
torsion is 56.61±9.57 and the mean angle of
retroversion is 33.39±9.57.
Table 1 represents the minimum, maximum and
mean value of torsion angles for males and females.
Table 2 represents the minimum, maximum and mean
of retroversion angles for males and females. Table 3
represents the summary of the average mean of angles
of torsion and retroversion for male and female.
Table 1: Summary of torsion angle values of both sexes
Side
Min.
Male
Right
25.0
Left
32.0
Female
Right
35.0
Left
20.0
No. of males: 200; Females: 34; Min: Minimum; Max: Maximum
Table 2: Summary of retroversion angle of both sexes
Side
Min.
Male
Right
7.0
Left
5.0
Female
Right
17.0
Left
13.0
No. of males: 200; Females: 34; Min: Minimum; Max: Maximum
Table 3: Summary of torsion and retroversion angle of both sexes
Sex
Average mean torsion angle
Male
56.63±2.08
Female
56.52±1.04
No. of males: 200; Female: 34
Max.
Mean
83.0
85.0
54.54±0.69
58.71±0.66
73.0
77.0
55.47±1.59
57.56±1.96
Max.
Mean
65.0
58.0
35.46±0.69
31.29±0.66
55.0
70.0
34.53±1.59
32.44±1.96
Average mean retroversion angle
33.38±2.08
33.49±1.04
Table 4: Showing large sample test to assess the significance of the difference in the means of right and left side angle of torsion in both sexes
Side
Means in degrees
Difference of means
S.E. difference of mean
Interference
Male
Right
No. of humeri = 200
Mean 54.54
S.D. 0.69
4.17
0.03
Significant
Left
No. of humeri = 200
Mean 58.71
S.D. 0.66
Female
Right
No. of humeri = 32
Mean 55.47
S.D. 1.59
2.09
0.37
Significant
Left
No. of humeri = 32
Mean 57.56
S.D. 1.96
Table 5: Showing large sample test to assess the significance of the difference in the means of right and left side angle of retroversion in both
sexes
Side
Means in degrees
Difference of means
S.E. difference of mean
Interference
Male
Right
No. of humeri = 200
Mean 35.46
S.D. 0.69
4.17
0.03
Significant
Left
No. of humeri = 200
Mean 31.29
S.D. 0.66
Female
Right
No. of humeri = 32
Mean 34.53
S.D. 1.59
2.09
0.37
Significant
Left
No. of humeri = 32
Mean 32.44
S.D. 1.96
176 Asian J. Med. Sci., 4(5): 174-178, 2012
Table 6: Showing large sample test to assess the significance of the difference in the means of right and left side angle of torsion in both sexes
Side
Means in degrees
Difference of means
S.E. difference of mean
Interference
Angle of torsion
Right
No. of humeri = 232
Mean 54.67
S.D. 9.62
3.88
0.1
Significant
Left
No. of humeri = 232
Mean 58.55
S.D. 9.52
Angle of retroversion
Right
No. of humeri = 232
Mean 35.33
S.D. 9.62
3.88
0.1
Significant
Left
No. of humeri = 232
Mean 31.45
S.D. 9.52
Fig. 4: Krahl's 'Torsiometer'. The original description of the
device is as follows: “The device comprises a plastic
protractor (A) and a pair of pointers (B) attached to a
shaft (C) passing through the protractor’s centre. The
protractor and shaft are mounted on a pivot (D) so that
the shaft may be swung from side to side if necessary.
To permit this swinging the support (E) must be
triangular in cross-section with the apex directed
forward. The whole is mounted on a solid base (Krahl
and Evans (1945)
This study finds the angle of humeral torsion to be
56.61±9.57°, with a minimum value of 22.5±1.33 and a
maximum value of 84.0±1.31, while angle of
retroversion is 33.39±9.57, with a minimum value of
9.0±1.31 and a maximum value of 67.5±1.33.
The angle of torsion of the right and left humeri,
been 54.67±9.46 and 58.55±8.54 respectively. The
observation in this study do not support the report of
greater right side torsion documented by Krahl and
Evans (1945), Debevoise et al. (1971) and Mehta and
Chaturvedi (1971) working on American whites and
Indian population. However this study agrees with
Krahl and Evans (1945) study on American Negros
which shows greater angle on left side than on the right
side as well as Broca (1881) who has done the most
extensive study of humeral torsion in 600 humeri of
various races also and found in nearly whole series the
torsion is greater in the left humerus than in the right.
Table 4 and 5 shows the significance of the
difference in the means of right and left side angles of
torsion and retroversion between males and females
specimen respectively. Table 6 shows the significance
in the means of the of the right and left side angles of
torsion and retroversion in both sexes. A positive
relationship exist between increased humeral torsion
and Recurrent Anterior Dislocation of Shoulder
(RADS), in that patients with RADS has a significant
increase in the angle of humeral torsion as compared to
persons without any history of RADS or shoulder
trauma (Debevoise et al., 1971; Kronberg et al., 1990;
Symeonides et al., 1995).
According to Kronberg et al. (1990) suggestion,
increased torsion of humeral head might predispose to
anterior dislocation by putting the head in a position of
risk in the abducted and external rotated position.
Symeonides et al. (1995) also indicated that less force
is needed for the first dislocation in shoulders with
reduced or absent retroversion. However in Randelli
et al. (1986) reports no difference in torsion between
normal shoulders and those with RADS (Shah et al.,
2006).
CONCLUSION
There exist a very wide range of distribution of
angles of humeral torsion and retroversion across
populations thereby making it very difficult to establish
a constant value. However this study has succeeded in
establishing a range of values of angle of torsion and
retroversion which in the clinical setting would enable
clinicians to improve clinical interpretation of
assessment findings to better make the diagnosis and
treatment choices for shoulder problems.
ACKNOWLEDGMENT
The authors wish to acknowledge Department of
Anatomy, Kampala International University Western
177 Asian J. Med. Sci., 4(5): 174-178, 2012
Campus and Department of Anatomy, Makerere
University Uganda for permission and support to carry
out this study.
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