Open Kinetic Chain (non weight-bearing tests)
1: Foot morphology and motion test
Relates to the general principles of open kinetic chain foot biomechanics; joint position and passive range of motion.
Non weight bearing alignment of the rear foot, forefoot and first ray is assessed while supported in subtalar joint neutral as per the ‘Root’ method.
This method gives the clinician the ability to assess and record individuals foot morphology as a ‘baseline’ which then assists in the understanding of the foot’s compensations underweight bearing conditions.
The range of available joint motion is assessed and identified at the ankle (dorsiflexion and plantar flexion), STJ (pronation and supination), MTJ (pronation and supination), 1st Ray (dorsiflexion and plantar flexion), and 1st MTPJ (dorsiflexion). Both restriction in joint range, as well as hypermobility (excessive range), give the clinician additional information to assist in understanding how and why the foot compensates in the way it does once weight bearing and during gait (functional).
Closed Kinetic Chain (weight-bearing tests)
2: Alignment test
The foot and lower limb alignment is examined in stance to determine if and/or how it compensates when weight bearing. This is related back to the non-weight bearing foot morphology test to assist understanding and help build a more ‘global’ picture of the individual.
Biomechanical principles are used to assess skeletal alignment. The patient is examined in relaxed stance, from both the front, side and the back, and weight bearing posture is noted. This may include relaxed calcaneal stance position, Foot Posture Index, navicular drift and drop, tibial stance, knee position, pelvis alignment, angle and base of stance as well as noting any skeletal deformity of the foot. Apparent mechanical “deformity” in the foot may be a compensation for joint and/or soft tissue restrictions in structures of the spine, pelvis, hips, knees or feet themselves.
3: Supination resistance test
The clinician manually supinates the foot and grades the force required from 1 to 5. The force required to supinate the foot is related to the position of the weight bearing axis of the subtalar joint and varies significantly from person to person. In gait this force is generated by both ground reaction forces and muscles in the foot and leg. The higher the supination resistance, the greater the pronatory forces and the greater the loading on the medial structures of the foot. Orthoses that reduce supination resistance decrease this loading and therefore can relieve or prevent symptoms.
4: Windlass (Jack's) test
Assesses the function of the windlass mechanism using the ‘Jack’s test’.
This clinical test assesses functional dorsiflexion range of motion availability of the hallux associated with heel lift and effective propulsion. The way in which the terminal slips of the plantar fascia wind around the metatarsal heads has been called the Windlass Mechanism (Hicks, 1954). The subtalar joint must supinate in order for the toes to dorsiflex. People vary greatly in the force required to dorsiflex the great toe to “activate the windlass mechanism”.
The clinician manually dorsiflexes the great toe until the foot supinates and grades the force required from 1 to 5.
Formthotics should decrease this force and improve the efficiency of gait.
5: Proximal control knee bend test
Assesses lumbopelvic postural stability and proximal control systems.
The patient is instructed to stand on one leg, establishing balance then closes their eyes. They then are asked to raise their arch for the foot to seek a “functional neutral position”, it then oscillates about this position.
Balance is eventually lost either medially or laterally. The clinician observes the stability of balance, the duration of balance, the “functional neutral position” and the loss of balance (medial or lateral). Relates to proprioception and postural stability.
Formthotics should improve the stability and duration of balance but should not induce lateral instability.
6: Neuromotor balance test
Efficient propulsion requires a stable base. The patient is instructed to stand on one foot and then rise up onto their toes. The clinician observes the ease of rising onto the toes, the stability and the tendency of inversion instability. Relates to propulsion.
Formthotics should improve stability and prevent inversion instability.
Option 1: Open/closed eye, single limb balance test
Option 2: Star excursion balance test
For the Forefoot stability test, observe the relative ease of rising onto the toes, stability and the tendency of inversion instability.