LOWER LEG, ANKLE, AND FOOT
SELECTED MOVEMENTS
Active movements of the lower leg, ankle, and foot should be done in both weight-bearing and non-weight-bearing positions (long leg sitting or supine lying), and the examiner should note any differences, because foot deformities and deviations, in addition to decreased range of motion (ROM), can lead to injury in other parts of the lower kinetic chain and spine.1
INDICATIONS OF A POSITIVE TEST
Plantar flexion of the ankle is approximately 50°. If the ROM is less than this or is less than for the unaffected leg, the movement is restricted for some reason. The patient’s heel normally inverts when the movement is performed in weight bearing. If heel inversion does not occur, the foot is unstable, or tibialis posterior weakness or tightness is present.2–4 The tibialis posterior muscle and tendon balance the pull of the peroneal muscles, protect the spring ligament, and invert and stabilize the hindfoot during toe-off.5
INDICATIONS OF A POSITIVE TEST
Dorsiflexion of the ankle is usually 20° past the anatomical position (plantigrade), which is with the foot at 90° to the bones of the leg. If the ROM is less than this or is less than for the unaffected leg, it is restricted for some reason.
INDICATIONS OF A POSITIVE TEST
Supination is 45° to 60°, and pronation is 15° to 30°, although individuals vary. If the ROM is less than this or is less than for the unaffected leg, it is restricted for some reason. It is more important to compare the movement of the affected foot with that of the unaffected foot. Supination combines the movements of inversion, adduction, and plantar flexion; pronation combines the movements of eversion, abduction, and dorsiflexion of the foot and ankle.
Toe Flexion, Extension, Abduction, and Adduction
The patient is asked to bilaterally flex the toes and then, in sequence, to extend, abduct, and adduct (“scrunch together”) the toes.
INDICATIONS OF A POSITIVE TEST
Extension of the toes occurs at the metatarsophalangeal and proximal and distal interphalangeal joints. Extension of the great toe occurs primarily at the metatarsophalangeal joint (70°); minimal or no extension occurs at the interphalangeal joint. For the great toe, 45° flexion occurs at the metatarsophalangeal joint, and 90° occurs at the interphalangeal joint. For the lateral four toes, extension occurs primarily at the metatarsophalangeal (40°) and distal interphalangeal (30°) joints.
Extension at the proximal interphalangeal joins is negligible. For the lateral four toes, 40° flexion occurs at the metatarsophalangeal joints, 35° occurs at the proximal interphalangeal joints, and 60° occurs at the distal interphalangeal joints. If the ROM is less than this or is less than for the unaffected leg, it is restricted for some reason.
Abduction and adduction of the toes are measured with the second toe as midline. Although the ROM of abduction can be measured, this is not usually done. The common practice is to ask the patient to spread the toes and then bring them back together (“scrunching” the toes). The amount and quality of these movements are compared with those of the unaffected side.
SPECIAL TESTS FOR NEUTRAL POSITION OF THE TALUS
Relevant Special Tests
Definition
The neutral position of the talus often is referred to as the neutral or balanced position of the foot. This so-called neutral position is an ideal position that, in reality, is not commonly found in people in normal weight bearing. For most patients, the subtalar joint and the calcaneus normally are in slight valgus, with the forefoot in slight varus. The tibia also is in slight varus, so each joint slightly compensates for the adjacent one. The neutral position is used as a starting position to determine foot and leg deviations. Functional asymmetry may occur in the lower limb in normal standing. If so, the examiner should put the talus in the neutral position to see whether the asymmetry remains. If it does, anatomical or structural asymmetry is a factor, as well as functional asymmetry. If the asymmetry disappears, only functional asymmetry is present, which often is easier to treat.
Suspected Injury
• Talar position tests are not designed to identify specifically any particular pathological condition; rather, they identify anatomical and biomechanical abnormalities that contribute to a pathological condition. That pathology may occur locally at the foot and ankle or remotely at areas such as the back, knee, or hip.
Epidemiology and Demographics
The overall prevalence of malalignment reported in the literature ranges from 10% in the Cheshire Foot Pain and Disability Survey in the United Kingdom to 28% in the Framingham Foot Study in the United States. Clinically, it has been hypothesized that abnormal talar alignment and mechanics can result in pathological conditions of the foot. Regardless of the prevalence of foot pain, the cause-and-effect relationship between talar position and pathological conditions has yet to be definitively determined.6–10
Relevant History
Patients with poor talar alignment or biomechanics may have a history of ankle sprains with or without talar dome osteochondral lesions. Ankle sprains may also result in talocrural instability or laxity, which could affect the position and mechanics of the talus in the ankle mortise.
Relevant Signs and Symptoms
The signs and symptoms depend on the pathological condition. Talar malalignment can manifest as pain in the foot, knee, hip, pelvis, or low back. Because talar malalignment results in compensations in other regions, most associated pathological conditions become problematic gradually. Generally, the patient cannot identify a specific mechanism of injury. Symptoms increase with use and lessen with rest. Positions or activities that require end-range dorsiflexion are the most problematic, because biomechanically, altered talus mechanics affect this most significantly. The ankle mortise must spread to accommodate the wider anterior aspect of the talus. If the talus is malpositioned, the talus may not be able to track through the mortise as efficiently or completely.
A sharp pain or pinching may be noted with end-range dorsiflexion. Hip lateral rotation or increased foot pronation may be noted during the middle to late stages of the stance phase of gait as a compensation for the lack of ankle dorsiflexion.
Mechanism of Injury
Malalignments may or may not be the result of previous injuries. Because of this, a mechanism of injury may or may not exist. Talar malalignment may be the result of previous injuries, repetitive use, leg length discrepancies, or genetics. Inversion ankle sprains may result in an osteochondral lesion, or bone bruise, on the medial aspect of the talus. Conversely, eversion ankle sprains can result in lesions or bruising on the lateral aspect of the talus. Either of these lesions, medial or lateral, could prevent proper tracking and alignment of the talus as it moves through the ankle mortise.
RELIABILITY/SPECIFICITY/SENSITIVITY COMPARISON11–16
| Validity | Interrater Reliability | Intrarater Reliability | |
| Neutral position of the talus (weight-bearing position) | Unknown | 0.15-0.79 | 0.14-0.85 |
| Neutral position of the talus (supine) | Unknown | Unknown | Unknown |
| Neutral position of the talus (prone) | Unknown | 0.25 | 0.06-0.77 |
NEUTRAL POSITION OF THE TALUS (PRONE)11–13,17–20 
To determine the neutral position of the talus, which often is referred to as the neutral (subtalar neutral) or balanced position of the foot.
Starting with the unaffected foot, the examiner grasps the foot over the fourth and fifth metatarsal heads with the index finger and thumb of one hand. The examiner palpates both sides of the talus on the dorsum of the foot, using the thumb and index finger of the other hand. The examiner then passively and gently dorsiflexes the foot until resistance is felt. Maintaining the dorsiflexed position, the examiner moves the foot back and forth through an arc of supination (the talar head bulges laterally) and pronation (the talar head bulges medially). The two feet are compared.
INDICATIONS OF A POSITIVE TEST
As the arc of movement is performed, there is a point in the arc at which the foot appears to fall off to one side or the other more easily. At this point, the talus should feel equally prominent on both sides (medial and lateral) of the talus. This point is the neutral, non-weight-bearing position of the subtalar joint. While holding this position, the examiner can observe the alignment of the leg relative to the calcaneus.
NEUTRAL POSITION OF THE TALUS (SUPINE)14,15,17–20 
To determine the neutral position of the talus, which often is referred to as the neutral (subtalar neutral) or balanced position of the foot.
Starting with the unaffected leg, the examiner grasps the foot over the fourth and fifth metatarsal heads, using the thumb and index finger of one hand. The examiner palpates both sides of the head of the talus on the dorsum of the foot with the thumb and index finger of the other hand. The examiner then gently and passively dorsiflexes the foot until resistance is felt. Maintaining the dorsiflexion, the examiner passively moves the foot through an arc of supination (the talar head bulges laterally) and pronation (the talar head bulges medially). The two sides are compared.
INDICATIONS OF A POSITIVE TEST
If the foot is positioned so that the talar head does not appear to bulge to either side (medial or lateral), the subtalar joint is in its neutral non-weight-bearing position.
NEUTRAL POSITION OF THE TALUS (WEIGHT-BEARING POSITION)11,13,16,18,21,22 
To determine the neutral position of the talus, which often is referred to as the neutral (subtalar neutral) or balanced position of the foot.
The patient stands with the feet in a relaxed standing position so that the base width and Fick angle (normally, the patella faces straight ahead while the foot faces slightly laterally) are normal for the patient.
The unaffected leg is tested first. The examiner palpates the head of the talus on the dorsal aspect of the foot with the thumb and forefinger of one hand (the thumb is placed on the lateral aspect of the talus and the forefinger is placed on the medial aspect of the talus). The patient then actively (or the examiner passively) slowly rotates the trunk to the right and then to the left, which causes the tibia to medially and laterally rotate so that the talus supinates and pronates. The two sides are compared.
INDICATIONS OF A POSITIVE TEST
If the foot is positioned so that the talar head does not appear to bulge to either side (medial or lateral), the subtalar joint is in its neutral position in weight bearing.
• Mueller et al.13 described a progression of neutral talus positions in standing (i.e., the navicular drop test) to quantify midfoot mobility and its effect on other parts of the kinetic chain. With a small, rigid ruler, the examiner first measures the height of the navicular from the floor in the neutral talus position, using the most prominent part of the navicular tuberosity; the height of the navicular in normal relaxed standing then is measured. The difference, called the navicular drop, indicates the amount of foot pronation or flattening of the medial longitudinal arch during standing. Any measurement greater than 10 mm is considered abnormal.
SPECIAL TESTS FOR ALIGNMENT
Relevant Special Tests
Suspected Injury
Alignment tests are not designed to identify specifically any particular pathological condition; rather, they identify lower leg, ankle, and/or foot anatomical and biomechanical abnormalities that may contribute to a pathological condition. That pathology may occur locally, at the foot or ankle, or remotely, at areas such as the back, pelvis, hip, or knee.
Epidemiology and Demographics
Few population-based studies have examined the prevalence of foot pain in the general population. Causal relationships between specific malalignments and injuries have been difficult to verify. In a random sampling of people in Australia, foot pain affected nearly 1 in 5 individuals. The pain was associated with increased age, female gender, obesity, and pain in other body regions, and it had a significant detrimental impact on health-related quality of life. The overall prevalence reported in this study was higher than that reported in the Cheshire Foot Pain and Disability Survey in the United Kingdom (10%). However, it was lower than the prevalence rates reported in two studies in the United States: the National Health Interview Survey in the United States (24%) and the Framingham Foot Study (28%).6–10
Relevant History
Often anatomical and biomechanical abnormalities can produce injury and pathological conditions in other regions of the body. Similarly, abnormalities in other regions may produce compensation in the body at the foot and ankle. Therefore, patients may have a history of injury or a pathological condition in other regions. Examination of the patient should include screening of the pelvis, hip, back, and knee, because a previous injury to these regions may produce foot and ankle malalignments. Injuries directly to the foot and ankle also may be present in many patients with malalignments.
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