Marker Placement

This is best performed with the rider on the bike. Before beginng to place the markers, inform the rider that you will be placing markers on them, which will require physical contact. Ensure that they are OK with this.

The marker locations are intended to be on the bones at the centre of joint rotation:

Foot: 5th Metatarsal

Palpate the outer side of the riders foot (just above the pedal axle is a good place to start) to find the most prominent bony protrusion. Place the marker here, slightly oriented to the upper side of the shoe so it is not pointing down.

Ankle: Lateral Maleolus

Place a thumb and finger either side of the bony protrusion of the ankle. Centre the marker between your digits.

If the rider is wearing ankle socks you may need to pull them higher, or try to push them down. Whatever is required to give the marker good contact in the correct position.

Knee: Distal Femoral Lateral Epicondyle

Ask the rider to set the cranks in the horizontal position, with the near foot forward.

Palpate just below and behind the Patella (kneecap) to find the gap between Femur and Tibia. Then palpate from the back of the knee to find the rear of that junction.

Place the marker centred on the bone between your finger and thumb.

Hip: Greater Trochanter

With the riders leg in extended position palpate to identify femoral head. If it is not clear where the bone is (common for all but the leanest riders) you may find that asking them to pedal backwards slowly causes the bone to pop out more clearly.

A useful technique for finding a starting point can be to ask the rider to sit up off the bars and place their hand on the side of their hip. With the heel of the hand at the top of their pelvis - the middle finger should extend to just over the greater trochanter.

Some types of lycra are particularly difficult to stick to. If you are having issues it can be worth using Kinesio tape to provide a larger base for the marker.

Also, riders will often wave their hands past their hips when off the bike - it can be worth asking the rider to hold their hand on this marker when they sit down off the bike so they are aware of the risk.

Shoulder: Greater Tuberosity of the Humeral head

Not on the Acromion as in other systems

With the rider sitting on the hoods locate the acromion process (end of clavicle) then move down roughly 3cm (1 inch) to find the head of the Humerus

When choosing the location, be sure to orient the marker such that it faces the Kinect as much as possible.

Elbow: Lateral Epicondyle

Palpate the riders elbow to find the end point of the Humerus. You may need to carefully choose where to place the marker to avoid having it folded over by the indent in the elbow.

Wrist: Centre of the Distal Radioulnar joint

If the rider is wearing a watch you will need to ask them to remove it. Place the dot in the centre of the top of the wrist.

You may need to place the marker slightly offcentre to orient towards the Kinect if the rider tends to twist their wrists. Or place the Kinect further towards the front of the bike.

 

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