Instrumented Measurement of Anteroposterior and Inversion-Eversion Laxity of the Normal Ankle Joint Complex

Abstract

Manual examination is the most common method for the evaluation of ankle anteroposterior (AP) and inversion-eversion (I-E) laxity. Objective assessment data of normal ankle laxity must be provided before comparison with an injured ankle can be made. The purpose of this study was to compare AP translation and I-E rotation at three force loads between dominant and nondominant ankles and to assess the test-retest reliability of a portable arthrometer in obtaining these measurements. The arthrometer consists of a frame that is fixed to the foot, a pad that is attached to the tibia, and a load-measuring handle that is attached to the foot plate through which the load is applied. A six-degrees-of-freedom spatial kinematic linkage system is connected between the tibial pad and the foot frame to measure motion. Instrumented measurement testing of total AP displacement and I-E rotation of both ankles was performed in 41 subjects (21 men and 20 women; mean age, 23.8 +/- 4.4 years). Subjects had no history of ankle injury. Subjects were tested in the supine position while lying on a table with the knee secured in extension and the foot positioned at 0 degrees of flexion. Laxity was measured from total AP displacement (millimeters) during loading to 125 N of AP force and from total I-E rotation (degrees of range of motion) during loading to 4000 N-mm. Reliability was evaluated by calculating intraclass correlation coefficients (2,1) at 75 N, 100 N, and 125 N of AP force and at 2000, 3000, and 4000 N-mm torque loads. Mean differences for displacement and rotation between the dominant and nondominant ankles at each of the force and torque loads were analyzed by dependent t-tests. For both the dominant and nondominant ankles, respectively, the reliability coefficients at each of the force loads for AP displacement (range, 0.82-0.89) and I-E rotation (range, 0.86-0.97) were high. The t-test analyses showed no significant differences (P > or = 0.05) for total AP displacement or I-E rotation between the dominant and nondominant ankles at any of the force loads. The results are clinically useful in providing information about the reliability of measures at different AP and I-E force loads using a portable ankle ligament arthrometer.

Arthrometric Measurement of Ankle-Complex Motion: Normative Values

“…[1][2][3] Valid and reliable measurements of the combined motions within the talocrural and subtalar joints (ankle complex) have been investigated fully and reported using the Hollis Ankle Arthrometer (Blue Bay Research, Inc, Navarre, FL). [3][4][5][6] Consisting of a 6-degrees-of-freedom spatial kinematic linkage, this device is described as a suitable evaluation tool that quantifies the anteroposterior (AP) load displacement and inversion-eversion (I-E) rotational characteristics of the ankle complex. 3,4,7 The Hollis Ankle Arthrometer has been used in a variety of clinical and research settings involving college-aged athletes and participants less than 25 years of age.…”

“…[3][4][5][6] Consisting of a 6-degrees-of-freedom spatial kinematic linkage, this device is described as a suitable evaluation tool that quantifies the anteroposterior (AP) load displacement and inversion-eversion (I-E) rotational characteristics of the ankle complex. 3,4,7 The Hollis Ankle Arthrometer has been used in a variety of clinical and research settings involving college-aged athletes and participants less than 25 years of age. Researchers have applied this type of arthrometric assessment in studies to biomechanically assess anklecomplex laxity in vivo and in vitro, 3,4,8 identify ankle instability after injury, [9][10][11][12][13] investigate the effects of sex and athletic status on ankle-complex laxity, 14 identify the relationship between ankle and knee ligamentous laxity and generalized joint laxity, 15 investigate the effects of balance training on gait in patients with chronic ankle instability, 13 investigate the effects of limb dominance on ankle laxity, 4 and assess the effectiveness of ankle taping.…”

“…3,4,7 The Hollis Ankle Arthrometer has been used in a variety of clinical and research settings involving college-aged athletes and participants less than 25 years of age. Researchers have applied this type of arthrometric assessment in studies to biomechanically assess anklecomplex laxity in vivo and in vitro, 3,4,8 identify ankle instability after injury, [9][10][11][12][13] investigate the effects of sex and athletic status on ankle-complex laxity, 14 identify the relationship between ankle and knee ligamentous laxity and generalized joint laxity, 15 investigate the effects of balance training on gait in patients with chronic ankle instability, 13 investigate the effects of limb dominance on ankle laxity, 4 and assess the effectiveness of ankle taping. 16 One limitation of using the Hollis Ankle Arthrometer and of using instrumented ankle arthrometry in general is that relatively small sample sizes have been reported and no normative data are available for comparison and reference.…”

“…16 One limitation of using the Hollis Ankle Arthrometer and of using instrumented ankle arthrometry in general is that relatively small sample sizes have been reported and no normative data are available for comparison and reference. [9][10][11][12][13][14] Kovaleski et al 4 investigated total AP displacement and I-E rotation between the dominant and nondominant ankles in a group of 41 male and female participants (age 5 23.8 6 4.4 years). Bilateral ankle comparisons showed no differences in ankle-complex laxity, and they reported mean total AP displacement of 18.47 6 5.1 mm for the dominant ankle and 17.51 6 5.4 mm for the nondominant ankle.…”

Analysis of ankle−hindfoot stability in patients with ankle instability and normals

“…Different authors recommended stressing the ankle in dorsiflexion, in the neutral position, or in plantarflexion during the stress manoeuvre [6,10,16,17]. The foot position affects ankle stability because the relationship between ligamentous laxity and bony constraints vary with flexion angle during stress testing [7,9,[18][19][20][21]. Our results showed that mobility of the ankle−hindfoot complex varied as foot flexion angle changed.…”