LOWER LEG, ANKLE, AND FOOT

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 |
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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