Radiographic monitoring of the distal insertion of the calcaneofibular ligament in anatomical reconstructions of ankle instabilities: A preliminary cadaveric study.

BACKGROUND: The purpose of the study therefore was to determine radiographic landmarks that support the identification of the insertion site of the distal calcaneofibular ligament (CFL) in anatomic ankle ligament reconstructions. METHODS: In 10 lower limb cadaver specimens the midpoint of the distal CFL insertion was dissected and marked with a nail inserted orthogonally. On a standardized lateral radiograph in neutral ankle position a horizontal tangent was aligned to the deepest visible concavity of the tarsal sinus and one vertical tangent to the farthest posterior convexity of the talus. Additionally, a line was drawn from the radiographically marked distal CFL to the fibular insertion of the CFL to determine the CFL-fibular angle. RESULTS: In relation to the radiographic tangents intersection the mean deviation of the depicted CFL nails was 2.2mm [SD ± 1.1 mm] leading to an angular, circular to slightly oval 6 mm insertion. The scatter-plot of the marked positions convened along a line from the supposed fibular CFL insertion to the intersection in all cases. The mean CFL-fibular angle was 131.7° [SD ± 3.16°]. CONCLUSIONS: Determining a virtual intersection between a horizontal tangent aligned to the deepest visible concavity of the tarsal sinus and one vertical tangent aligned to the farthest posterior convexity of the talus on a standardized lateral radiograph in neutral ankle position supports an anatomic insertion of the distal calcaneofibular ligament most probably.

Moment-knee angle relation in well trained athletes.

The purpose of this work was to investigate whether different modes of long-term competitive physical activity cause functional differences in the moment-knee angle relation of the M. quadriceps femoris (QF). Therefore, a sample (n = 40) of young male competitive endurance runners, cyclists, triathletes and tennis players performed isometric maximal voluntary knee extensions (MVC) with their stronger leg at six different knee joint angles while keeping the hip joint angle constant. Muscle activation of QF-muscles during MVC was estimated using surface electromyography (EMG). Moments and EMG data of each subject were normalized to the largest value produced at any knee joint position [% Max.]. No significant differences in the normalized [% Max.] moment-knee angle relation of the QF were found between endurance runners, cyclists and triathletes. Despite few unsystematic exceptions, no functional differences in the normalized moment-knee angle relation of the QF occurred among tennis players and the endurance-oriented athletic groups. Obtained by curve fitting, the optimal knee joint angle for moment production was not significantly different among all athletic groups. We conclude that long-term competitive endurance running, cycling, triathlon and tennis do not provoke functional differences in the moment-knee angle relation of the whole QF.

Changes in gait patterns in 10-year-old boys with increasing loads when walking on a treadmill.

This study examined the gait pattern, heart rate and blood pressure in children carrying school bags of 0 (as control), 10, 15 and 20% of their own body weight whilst walking on a treadmill. When compared to the 0% load condition, the 20% load condition induced a significant increase in trunk forward lean, double support and stance duration, and decreased trunk angular motion and swing duration and a prolonged blood pressure recovery time. The 15% load condition induced a significant increase in trunk forward lean and prolonged blood pressure recovery time. No significant difference was found in the measured parameters between the 10 and 0% load conditions. We concluded that back pack weight should not exceed 10% of body weight in 10-year-old boys.