OJHAS Vol. 8, Issue 3: (2009
between subtalar varus angle and disability in patients with patellofemoral arthritis
Gauri Shankar, Asst. Professor
KJ Pandya College of Physiotherapy, Sumandeep Vidyapeeth University, Pipariya, Waghodia Road,
Vadodara- 391760, Gujarat, INDIA
Address For Correspondence
KJ Pandya College of Physiotherapy,
Sumandeep Vidyapeeth University,
Pipariya, Waghodia Road,
Vadodara - 391760
Patel BJ, Shankar G. Correlation
between subtalar varus angle & disability in patients with
patellofemoral arthritis. Online J Health Allied Scs.
Submitted: Apr 24, 2009; Accepted:
Nov 2, 2009; Published: Nov 15, 2009
To find the correlation between subtalar
varus angle & disability in patients with patellofemoral arthritis. Methods: A total of 30 subjects aged (48.86±5.74)
referred to the department of physiotherapy, with patellofemoral arthritis
and fulfilling the criteria of inclusion were recruited for the study,
sampling method being convenient sampling. Disability score was
measured of each patient by WOMAC index (Western Ontario and McMaster
Universities Index of Osteoarthritis) disability questionnaire and
subtalar varus angle was measured in non weight bearing position in
prone lying. Results: Pearson’s correlation coefficient
test showed a highly significant (p=0.000) positive correlation (r=0.821)
between disability scores and subtalar varus angle. Conclusion: There is a highly significant relation
between disabilities due to patellofemoral pain in patellofemoral arthritis
patients and sub talar varus angle
Key Words: Patellofemoral arthritis, Subtalar
varus angle, Rear foot, Disability, Osteoarthritis knee
Knee Osteoarthritis (OA) is
a commonly encountered pathological joint affliction that leads to chronic
disability, reduced mobility and functional limitation.
OA in particular causes degeneration of the entire knee joint affecting
the integrity of the joint arrangement and could result in chronic disability.
Rear foot varus was found to
be one of the most common bony deformities of the foot which is present
in 83% of a normal population.[3,4] It was suggested however that subjects
with patellofemoral pain (PFP) had higher incidence of rear foot varus
It was reported a varus rear foot posture of subjects with PFP when
measuring subtalar joint neutral. Therefore, rear foot varus was suggested
to be a factor in contributing to PFP.
Thus rear foot varus may be a factor in contributing to PFP.
have shown relation between patellofemoral pain & subtalar varus
angle, but there have been minimal studies done on the relationship
between disability due to patellofemoral pain and subtalar varus angle
in cases with identical clinical findings and distribution of symptoms.
aimed at establishing a relationship if any between subtalar varus angle
and disability in patient with patellofemoral pain.
A total of 30 subjects aged
(48.86±5.74) referred to the department of physiotherapy, Dhiraj General
Hospital, Baroda, Gujarat with patellofemoral arthritis and fulfilling
the criteria of inclusion and exclusion were recruited for the study,
sampling method being convenient sampling.
All subjects were informed
of the procedures and signed a written informed consent prior
to participation in this study .
- Age – 40 to 65
- Sex – both males
- Clinically and radiographically
diagnosed patient of patellofemoral arthritis with unilateral involvement.
- Patellar dislocation
- Knee surgery
- Concomitant diagnosis
of prepatellar bursitis or tendonitis
- Ligamentous knee
injury or laxity
- Plica syndrome
- Bilateral involvement
of patellofemoral arthritis
- Sinding Larsen’s
- Osgood Schlatter’s
- Womac index
- Pencil and
- Sliding Calipers
of this study are the following.
- Measurement of
with petellofemoral arthritis with unilateral involvement were selected
& their disability scores were taken on WOMAC index disability questionnaire
on the first day before starting any physiotherapy interventions and
any medical treatment
- Measurement of
subtalar varus angle
laid down in prone position with the foot and ankle (to be measured)
hanging 15-20 cm over the end of the table. The opposite limb was positioned
in hip flexion, abduction and external rotation with the knee flexed
and resting on the supporting surface.
With the foot perpendicular to the floor the examiner bisected the posterior
lower leg and the posterior calcaneus using Sliding Calipers. The palpation
method of measuring the Subtalar Joint Neutral position was based on
and Elveru et al. The
foot to be measured was in dorsiflexion and the rear foot passively
pronated and supinated. When the head of the talus was felt equally
between the lateral and medial sides, the subtalar joint was in neutral
The position of the subtalar in the neutral position was maintained
and the angle formed by the longitudinal midline of the posterior calcaneus
and the line drawn on the posterior lower leg was measured.
One arm of the goniometer was placed on the lower leg bisection line
while the other arm was placed on the calcaneal bisection line .The
axis of the goniometer was placed between the malleoli in the frontal
analysis was done with the help of SPSS software by Pearson’s correlation
coefficient test. Significance was accepted at p <
significant at the 0.01 level
There was a
highly significant (p=0.000) positive correlation (r=0.821) between
disability scores and sub talar varus angle.
The result analysis shows that
null hypothesis can be cancelled, so it is clear that there is a relationship
between subtalar varus angle and disability in patellofemoral arthritis.
relationship between the subtalar joint and the lower extremity has
been well documented.[3,9-12]
The motions of pronation and supination occur at the subtalar joint
and assist in normal locomotion.
subtalar joint pronation occurs during the first 25% of the gait cycle
during which the tibia internally rotates 200.
This is in response to the inward rotation of the talus as it falls
into the space created by the inferior and lateral movement of the anterior
portion of the calcaneus.
Subsequent supination results in external rotation of the tibia. Transfer
of subtalar joint motions to the lower extremity is due to the tight
fit of the talus into the ankle joint mortise.
subtalar joint pronation has been described as a compensatory mechanism
for rear foot varus.[10-12]
Particular concerns are the bony foot
deformities that functionally invert the rear foot relative to the ground.
In order to achieve medial rear foot and forefoot contact during gait,
excessive subtalar joint pronation is required. Subtalar joint pronation
required to compensate for a bony deformity is considered abnormal if
the amount of pronation is in excess of the normal amount needed for
locomotion or occurs at the wrong time (when the foot should be supinating).
Excessive pronation will delay the
external rotation of the tibia which normally accompanies subtalar joint
If excessive or prolonged pronation is evident in midstance, then excessive
internal rotation of the tibia will be evident.
To achieve knee extension during mid stance, the tibia must externally
rotate relative to the femur to ensure adequate motion for the screw-home
mechanism. In order to compensate for this lack of tibial external rotation
as a result of abnormal pronation, the femur internally more predisposed
to patellofemoral pain than others.
Support for a
relationship between ankle and knee kinematics has been presented by Eng and
found that the correction of structural foot abnormalities with soft
foot orthotics resulted in small changes in frontal and transverse motion
at the knee. In a follow up study, the same authors reported that use
of this orthotics was more effective in reducing patellofemoral pain
than a traditional exercise program.
Although a small patient group was studied, these results gave clinical
credence to this biomechanical relationship.
Rear foot varus was found to be one of the most common bony deformities
of the foot which is present in 83% of a normal population.
The present study shows that subjects with patella femoral pain syndrome
(PFPS) have higher incidence of rear foot varus deformity which is similar
with the study of Powers et al.
& Pazit leveinger and Wendy Gillieard.
Thomee et al. reported no differences in the Relaxed Calcaneus
Standing (RCS) angle relative to the lower leg or to the horizontal
between controls and subjects with PFPS.
The current study is an attempt at establishing a relationship between
sub talar varus angle and disability in symptomatic subjects with comparable
clinical presentation. The study was carried out on subjects from Baroda,
a city in western India. Disability of subjects measured with The
(Western Ontario and McMaster Universities) Index of Osteoarthritis
and the sub talar varus angle
measured by using non weight bearing position in prone position. Present
study shows a very highly significant positive correlation between sub
talar varus angle and disability scores on The WOMAC (Western Ontario
and McMaster Universities) Index of Osteoarthritis (r=0.821, p=0.000).
Certain variables were uncontrolled in the current study and their influence
on the results was assumed to be null. The major assumption was regarding
the drugs prescribed by the orthopedician. The effect of drugs could
definitely be a direct confounding factor for the pain intensity. But
for the credit of the current study the entire outcome measures were
collected on the first day of diagnosis before any noticeable effect
of the medications would have set in.
It has been
proved that there is a highly significant relation between disabilities
due to patellofemoral pain in patellofemoral arthritis patients and
subtalar varus angle, but further studies with different set of variables
and situation are required to substantiate the current findings.
One major limitation
of the current study was the sample size. Though the result obtained
was very highly significant, to generalize the findings into a clinically
useful data the study has to be replicated in a bigger sample size.
study was done of subjects grouped on the basis of anatomical distribution
of symptoms. Grouping the subjects on the basis of pathology rather
than symptom distribution may give a better insight into the interaction
between disability and biomechanical factors. If the uncontrolled variables
of the current study could be controlled, the sensitivity and specificity
of the findings can be increased.
should aim at the interaction of multiple variables in the manifestation
of patellofemoral pain. Future studies could be done with the aim at
studying both the genders separately to obtain a more accurate and specific
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