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Biomedical subjects

F G Lippert

Publications and source records attributed to F G Lippert.

13 recordsLinked to original sources
PubMed1991

Crescentic osteotomy for hallux valgus: a biomechanical study of variables affecting the final position of the first metatarsal.

The position of the first metatarsal following a crescentic osteotomy for hallux valgus is a function of the size of the saw cut and orientation of the osteotomy. This study reports the effect of these variables, recommended technique, and potential pitfalls when using the crescent osteotomy. Using molded polyurethane foam metatarsals and a precision drill press which controlled the saw cuts, the following variables were studied: (1) orientation of the saw cut to the metatarsal, (2) the saw size (diameter of the saw relative to the shaft width of the osteotomy site), and (3) the direction toward which the crescent faces (proximal/distal). Best correction can be obtained if the saw diameter is larger than the diameter of the osteotomy site (allowing a greater degree of correction before impingement), the saw tip is tilted slightly toward the sesamoids (which ensures that the metatarsal does not rotate medially with correction), and the saw is rotated laterally to cause slight declination of the toe.

Biomechanical Phenomena↗
PubMed1987

The generic shoe: a prescription tool.

A multiple-use testing shoe capable of various orthotic modifications has been developed. Its use in predicting prescription performance and patient compliance is presented. Patient compliance is enhanced by understanding gained through the testing procedure.

Biomechanical Phenomena↗
PubMed1979

Biomechanical study of the pitching elbow.

Medial-tension injuries of the pitching elbow are well recognized. One contributing factor is the extreme valgus which has been noted to occur during the acceleration phase of throwing. It is hypothesized that breaking pitches generate higher medial loading because of the pronation and supination required to impart spin to the ball. The pitching motion is a complex action of all body segments to produce maximum linear and angular acceleration of the ball. The purpose of this study was to correlate elbow loading with pitching style. We measured the forearm segment for axial and tangential (varus-valgus plane) acceleration using accelerometers attached to the forearm and hand. Muscle activity was measured by EMG. Forearm rotation was assessed by stroboscopic photography. Despite different delivery styles when throwing breaking pitches, each pitcher demonstrated patterns of muscle activity and acceleration which were similar. Deceleration forces were lower than acceleration forces. Pronation and supination were documented and contribute to the direction of ball spin. Accelerometers can be used to evaluate pitching mechanics. We suggest that the main factors causing an elbow injury are the amount of throwing and the force with which the ball is thrown.

Baseball↗
PubMed1977

Instability of the subtalar joint. Diagnosis by stress tomography in three cases.

Lateral instability in the subtalar joint was documented by a method of stress tomography in three patients. The subtalar inversion angle averaged 38 degrees +/- S.D. 6 degrees in asymptomatic feet and 57 degrees +/- S.D. 5 degrees in those with unstable subtalar joints . Review of the literature suggests that as many as 10 per cent of patients having the Watson-Jones procedure for abnormal talar tilt also have instability in the subtalar joint. It is felt that the subtalar joint should be evaluated in patients seen with the clinical symptom of lateral instability.

Adult↗
PubMed1975

A jig for pin insertion in the performance of high tibial osteotomy.

The crucial step in high tibial osteotomy is to translate the computed angle of correction into a bone wedge outlined by 2 Kisrchner wires to guide the surgery. The wedge can be excised with precision in 2 planes. A jig facilitates accurate placement of the pins to correspond exactly to the predetermined angles.

Arthritis↗