Proximal Radioulnar Joint Mobilizations

Set-Up

1. The patient should be supine, with the hand of the affected side resting on their stomach, and the practitioner standing on the patient's affected side.
2. Placing a dowel, foam roll, or pillow under the patient's forearm can be helpful for improving mechanics.
3. The table should be at a high level to allow the practitioner to apply force horizontally, without having to excessively bend or crouch. The dowel will change the position of the forearm enough to allow for a more natural angle to apply force for the practitioner (oblique angle that is both forward and down).

Posterior to Anterior Mobilization

1. Palpate the radial head by falling of the olecranon process cranially and medially, or by gripping and palpating through the brachioradialis. Once you feel a hard bony protuberance, test your palpation by passively pronating and supinating the forearm with one hand, while palpating what you think is the radial head with the other hand. You should feel the radial head "spin" under your fingers.
2. Once, you have determined the location of the radial head, "gather some skin" from on top of the radial head and pull it posteriorly as you press into the extensor mass just posterior to the radial head.
   • If you do not "gather some skin", you can end up locally stretching the skin as you apply pressure, which may be painful for the patient.
3. Use one thumb to gain purchase on the back of the radial head. Wrap the radial head with the thumb to avoid "poking", by putting the radial head in the interphalangeal joint of the thumb.
4. Place the other palm over your thumb, straighten the arms, and ensure optimal body mechanics.
5. Generate force by leaning forward at the torso, using bodyweight, not grip or arm strength.

A study by Ohshiro et al. demonstrated that glide during anterior/medial radius mobilizations was greatest during 60° - 90° of elbow flexion, and glide during posterior/lateral radius mobilizations was similar at all elbow flexion angles (28). These findings suggest that for the mobilization technique above 60° - 90° of elbow flexion is likely best.

Anterior to Posterior Mobilization

The technique for this is identical to the technique above. However, you are going to stand next to the patient's head and force will be applied in the opposite direction.

1. Palpate the radial head by falling of the olecranon process cranially and medially, or by gripping and palpating through the brachioradialis. Once you feel a hard bony protuberance, test your palpation by passively pronating and supinating the forearm with one hand, while palpating what you think is the radial head with the other hand. You should feel the radial head "spin" under your fingers.
2. Once, you have determined the location of the medial head, "gather some skin" from on top of the radial head and pull it anteriorly as you press into the brachioradialis just anterior to the radial head.
   • If you do not "gather some skin", you can end up locally stretching the skin as you apply pressure, which may be painful for the patient.
3. Use one thumb to gain purchase on the back of the radial head. Wrap the radial head with the thumb to avoid "poking", by putting the radial head in the interphalangeal joint of the thumb.
4. Place the other palm over your thumb, straighten the arms, and ensure optimal body mechanics.
5. Generate force by leaning forward at the torso, using bodyweight, not grip or arm strength.

Mobilization:

1. Once you are comfortable with palpating joint motion, start with small test oscillations to identify articular motions and any exquisite tenderness.
2. When satisfied with the feel of the technique, identify the amount of pressure needed to feel the first resistance barrier just prior to articular motion, and then pressing harder, identify the amount of pressure at which any further pressure fails to increase articular motion.
   • Note: The end of articular motion is the end of glide. Locate the point at which the joint will not glide any further without additional extension.
3. Identify the mid-point between the first resistance barrier and articular end-range; approximately 50% resistance.
   • Grade III - Larger oscillations between the first resistance barrier and approximately 50% resistance.
     • Note, these oscillations are large compared to grade IV oscillations, but are still very small motions.
   • Grade IV - Small oscillations at 50% resistance or more.
4. Oscillate at 1 - 2 pulses per second.
5. Continue oscillating until you feel a change in tissue resistance/joint stiffness.
   • Note: Feeling resistance barriers and relative motion is challenging with this technique due to the hand position and relatively small amount of arthrokinematic motion allowed at the joint. Don't let perfect be the enemy of the good. Mobilizing the joint and decreasing stiffness is more important than a perfectly executed grade III, or being able to differentiate between a grade III and a grade IV.