What are the required subject measurements for Plug-in Gait?

The measurements required for both upper and lower body models include mass, height, leg length, knee width, ankle width, shoulder offset, elbow width, wrist width, and hand thickness.

These measurements should all be entered in either kilograms or millimetres. All lengths or distances will be required in millimetres. The measurements for inter-ASIS distance, ASIS-trochanter distance, and tibial torsion are all optional entries. If they are not entered in, the model will calculate them.

Here are the precise required measurements for the model:

Mass: The mass of the subject in Kilograms (2.2lb=1kg)

Height: The height of the subject.

Leg length: Measured from the ASIS to the medial malleolus. If a patient cannot straighten his/her legs, take the measurement in two pieces: ASIS to knee and knee to medial malleolus.

Knee width: Measurement of the knee width about the flexion axis.

Ankle width: Measurement of the ankle width about the medial and lateral malleoli.

Shoulder offset: The vertical distance from the center of the glenohumeral joint to the marker on the acromion clavicular joint. Some researchers have used the (anterior/posterior girth)/2 to establish a guideline for the parameter.

Elbow width: The distance between the medial and lateral epicondyles of the humerus.

Wrist width: Should probably be called "wrist thickness." It is the distance between the anterior (palm side) and posterior (back) side of the wrist in the anatomical position.

Hand thickness: The distance between the dorsal and palmar surfaces of the hand at the point where you attach the hand marker.

The following measurements are optional and/or calculated by the model:

Inter-ASIS distance: The model will calculate this distance based on the position of the LASI and RASI markers. If you are collecting data on an obese patient and cannot properly place the ASIS markers, place those markers laterally and preserve the vector direction and level of the ASIS. Palpate the LASI and RASI points and manually measure this distance, then input into the appropriate field.

Head Angle: The absolute angle of the head with the global coordinate system. This is calculated for you if you check the option box when processing the static trial.

ASIS-Trochanter distance: The perpendicular distance from the trochanter to the ASIS point. If this value is not entered, then a regression formula is used to calculate the hip joint center. If this value is entered, it will be factored into an equation which represents the hip joint center.

Tibial torsion: The angle between the ankle flexion axis and the knee flexion axis. The sign convention is that if a negative value of tibial torsion is entered, the ankle flexion/extension axis will be adjusted from the KAD's defined position to a position dictated by the tibial torsion value.

Thigh rotation offset: When a KAD is used, this value is calculated to account for the position of the thigh marker. By using the KAD, placement of the thigh marker in the plane of the hip joint center and the knee joint center is not crucial. Please note that if you do not use a KAD, this value will be reported as zero because the model is assuming that the thigh marker has been placed exactly in the plane of the hip joint center and the knee joint center. This value is calculated for you.

Shank rotation offset: Similar to the thigh rotation offset. This value is calculated in a KAD is present and removes the importance of placing the shank marker in the exact plane of the knee joint center and ankle joint center. If you do not use a KAD, these values will be zero. This value is calculated for you.

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