Home Functional Hallux Limitus Diagnosis Podiatric assessment
Diagnosis
The podiatric assessment, the footprint that signs FHL
The plantar footprint is the instant signature of how the foot works. The podiatric assessment objectifies, measures and photographs the anomalies that a clinical examination alone cannot document, with one pathognomonic sign systematically found in FHL.
Diagnosis section
The footprint, an instant signature of the foot
The plantar footprint is, in a sense, the signature of how the foot works and of our balance. It is an instant trace that almost allows one to extrapolate, by deduction, the position of the upper body in balance, thanks to the inter-articular synchronism that links every movement of the foot to that of the levels above. Knees, hips and back depend closely on the position of the foot, and the footprint tells the story of them all indirectly.
Two complementary tools
The podiatric assessment at the Centre du pied relies on two complementary tools: the static podoscope for visual observation and the ultra-sensitive sensor mat for dynamic measurement. One shows, the other quantifies.
Tool 1
Transparent-plate podoscope
Static examination on a backlit transparent plate that highlights the pressure points. The clinician directly observes the distribution of the load over the sole of the foot. A simple, quick method that is particularly telling for the patient.
Tool 2
Ultra-sensitive sensor mat
A mat equipped with sensors that measure plantar pressures in real time, first statically and then dynamically while walking. It quantifies the displacement of the center of gravity, the zones of excessive and reduced loading, and the kinetics of the foot roll-through.
The static footprint characteristic of FHL
On the podoscope, the footprint of a patient with FHL shows a characteristic silhouette. Three zones deserve particular attention, because they sign the diagnosis.
FHL footprint — three visual markers
The static footprint of someone with FHL shows three characteristic signs on the podoscope.
The sign that makes the diagnosis
No contact under the M1 head, pathognomonic of FHL
The absence of contact under the head of the first metatarsal (M1) is pathognomonic of FHL. This characteristic void on the footprint means that the foot no longer loads the first ray normally, a direct consequence of the blocked FHL tendon and the tenodesis effect. When this sign is present, the diagnosis is strongly oriented.
The racket-shaped aspect of the big toe
When the first metatarsal no longer bears load, the load is transferred to the pulp of the big toe, which becomes overworked. This overload shows as a widened, emphatic contact under the pulp, whose silhouette suggests a racket or a spoon. It is the complementary sign to the absence of contact under M1.
Dynamic analysis on the sensor mat
The podiatric assessment performed on the mat includes two complementary analysis modes. A static analysis on both feet and then on one foot, which shows the projection of the center of gravity at rest. And a dynamic gait analysis, which reveals what observing the footprint alone cannot document, namely the chronology of the foot roll-through and the pronation-supination transitions.
Six signs systematically found. In patients with FHL, dynamic analysis on the mat brings out six biomechanical signs that are almost always found together. Their combination constitutes a very strong diagnostic signature.
1. Static — Center of gravity shifted backward and laterally. The projection is abnormally set back and displaced outward.
2. Dynamic — Heel strike on the lateral edge. Lateral initial contact, roll-through shifted laterally.
3. Dynamic — Shifted pronation-supination transitions. Desynchronized changeover, destabilizing rolling effect.
4. Dynamic — Abrupt tilt into pronation at late stance. A true break in the movement instead of a progressive tilt.
5. Static and dynamic — Excess loading under the pulp of the big toe. Abnormally high load, a consequence of the transfer.
6. Static and dynamic — No contact under the M1 head. The most specific sign, considered pathognomonic.
Diagnostic strength
None of these signs taken in isolation makes the diagnosis, but their association is almost pathognomonic of FHL. The combination of the shifted center of gravity, the lateral heel strike, and the absence of contact under M1 constitutes a cluster of arguments that is difficult to explain other than by a tenodesis effect of the FHL tendon.
Usefulness for diagnosis and follow-up
The podiatric assessment serves a dual purpose at the Centre du pied. It objectifies the diagnosis at the initial consultation, in addition to the in-office clinical test. And it serves as a reference for evaluating the effectiveness of treatment, whether conservative or surgical, by comparing the assessments before and after care.
« The footprint does not lie. It tells what the patient feels and what they do not yet feel, in the silence of a load that has been poorly distributed for years. »
Dr Jacques Vallotton, Centre Orthopédique d’Ouchy
Understand it on video
Several video sequences illustrate the contribution of podiatry to the assessment, from the podiatry and footwear workshops to gait assessments and lectures from the Medicol Congress.
Comprehensive therapeutic approach and the contributions of podiatry
FHL Workshops 2016 — Footwear workshop
FHL Workshops 2016 — Podiatry and occupational therapy workshop
Gait assessment and podiatric analysis — Dr Theresa Olden
Gait assessment and analysis
Dr Gkavardina & Rappaz — The value of the gait and functional assessments
Next step
Examine the shoes, the final clue
After the footprint on the ground, examining the shoes usefully completes the assessment. Their asymmetric wear tells the story of years of disorganized walking.
At a glance
Tools
2, complementary
Analysis modes
static + dynamic
Pathognomonic sign
absent M1 contact
Complementary sign
racket-shaped hallux
Dynamic signs
6 found
Post-treatment follow-up
comparable