Transcript Positional Relationship of the Fibula Relative to the Tibia in

Positional Relationship of the Fibula Relative to the Tibia in
Collegiate Athletes
Katherine Lane
Introduction
Faculty Mentor: Alice Fazlollah, MS
Department of Geography and Anthropology Results
This research asses the relationship between the crosssectional geometric (CSG) properties of the tibia and
fibula. CSG properties can tell physical anthropologists
about the kinds of activities individuals in past
populations may have engaged in. Modern athletes can be
used as a model to understand these relationships.
Wolff’s Law states that bone form follows function, or that
when stresses are placed on bone, the bone will remodel
through either absorption or deposition in order to
maintain optimal strain levels. The majority of research in
cross-sectional bone geometry has been on the femur, and
that which has been examining the lower leg usually
focused only on the tibia. The fibula has managed to
escape the focus of research due to the assumption of its
lack of importance due to its lesser weight bearing
capabilities.
•
Subgroups participated in the following activities: field
hockey (15), distance runners (15), swimmers (15),
cricketers (16), and non-athletes (20).
pQCT scans were imported into ImageJ
(http://rsb.info.nih.gov/ij/) and analyzed using BoneJ
(http://bonej.org/).
Distance and angle were examined against CSG
properties.
•
When examined by sporting groups, field hockey
players and cricketers stood out. These two groups
had no correlation between distance and Iy (while
runners, swimmers, and controls had a positive
correlation), and had a positive correlation between
angle and Iy (while the other groups had no
correlation).
Discussion
0.008
R² = 0.3346
Control (Non-athletes)
0.007
•
These results could be indicative of the different
loading patterns of field hockey players and cricketers.
These two groups have a more multidirectional,
especially mediolateral, loading patterns versus the
more anterior- posterior loading patterns of runners
and swimmers.
•
The results suggests that the fibula could help mediate
the forces applied to the tibia especially when the
fibula is aligned more in the mediolateral aspect.
•
Further research on the relationship between the angle
and cross-sectional geometric properties of the fibula
and tibia would benefit from a study with larger
sample sizes.
Runners
Control (Non-Athletes)
R² = 0.2227
Runners
0.006
0.005
0.004
5.00E-06
6.00E-06
7.00E-06
8.00E-06
9.00E-06
1.00E-05
1.10E-05
1.20E-05
1.30E-05
Distance Between Centroids
Fig. 3 Controls and runners demonstrated significant positive correlation
(P ≤ 0.05) between M-L bending rigidity and distance between the
centroids.
0.01
0.009
0.008
R² = 0.2289
Selected References
Hockey Players
0.007
Cricketers
R² = 0.0721
Hockey Players
Cricketers
0.006
0.005
0.004
3E-08
•
For the tibia there was a positive correlation between
angle and Iy (mediolateral rigidity), and for the fibula
there was a positive correlation between angle and Iy
and J (torsional rigidity).
0.009
M-L Bending Rigidity
•
83 males between the ages of 18 and 30 years old and that
have been participating in competitive sports since
childhood/ early adolescence.
•
0.01
Materials and Methods
•
A positive correlation exists between distance and all
cross-sectional geometric properties for both bones.
Fig. 2 Example screen shot of
ImageJ program showing results.
Fig. 1 Example pQCT scan
of the left tibia/ fibula at
50% of diaphyseal length.
M-L Bending Rigidity (Iy)
This study examines the correlation between the distance
and angle between the tibia and fibula and tibial
robusticity in different mobility groups. It was
hypothesized that the greater the distance between the two
bones would result in a less robust tibia, and, vice versus,
the lesser the distance between the tibia and fibula would
result in a more robust tibia. With the angle, it was
hypothesized that the closer the fibula was positioned in a
mediolateral plane results in a less robust tibia in the
mediolateral aspect.
•
4E-08
5E-08
6E-08
7E-08
8E-08
9E-08
0.0000001
1.1E-07
Angle Between Centroids
Fig. 4 Hockey players and cricketers demonstrated significant positive
correlation (P ≤ 0.05) between M-L bending rigidity & angle between
centroids.
Shaw CN, and Stock JT.
2009. Intensity, repetitiveness, and directionality of habitual adolescent
mobility patterns influence the tibial diaphysis morphology of athletes.
American Journal of Physical Anthropology 140(1):149-159.
Marchi D & Shaw CN.
2011. Variation in fibular robusticity reflects variation in mobility
patterns. Journal of Human Evolution 61(5):609-616
Goh JC, Mech AM, Lee EH, Ang EJ, Bayon P, and Pho PW.
1992. Biomechanical study on the load-bearing characteristics of the fibula and the effects of fibular
resection. Clin Orthop Relat Res (279):223-228.