The Brock String is the basis for some wonderful activities, helpful in developing visual skills. Brock Strings are used to
- Create awareness of space and depth.
- Increase the range of motion of the eyes.
- Increase accuracy and range of targeting.
- Improve scanning ability.
ROM VOR Pursuits 2
ROM means ‘range of movement’, that is, this activity is designed to increase the range of movement of the eyes. Movements of particular interest in the classroom include inwards and outward movements of the eyes. This activity is designed to encourage greater range generally, while other activities are concerned with more specific areas of concern. Increasing functional ranges are not so much a matter of ‘stretching muscles’ as reminding the brain that the eyes can move in a broader range than they normally do during day to day living.
VOR refers to the human vestibulo-ocular reflex, which automates the tracking of objects as the head moves. For example, continue reading this text while moving your head from side side. The VOR uses the sense of balance to automatically move the eyes so you can continue with the complicated task of reading. Activating this reflex engages yet another brain system that is more automatic than voluntary and can help to achieve greater range than by simply calling on voluntary impulses alone. In some instances, even what looks like ‘locked-in’ problems with eye turns can be addressed by stimulating reflex movements such as the VOR.
In these exercises, you will use the Brock String with one bead to engage one of two key visual reflexes to assist in building range of movement of the eyes. Other Brock String activities will engage more voluntary eye movements, that is, those movements we direct our eyes to make. Voluntary movements require more input and processing from the frontal lobes and is generally more tiresome. Voluntary eye movements are generally slower compared to reflexes. The Saccades activity helps with voluntary saccades of the type required for reading automaticity. Other activities on the site help with involuntary saccades and visual motor integration.
- Glasses should be worn.
- Begin with the Starting Position, described in Physiological Diplopia: When seeing double is correct. Use only one bead positioned at the Harmon distance. Let the remaining beads drop to the far end of the string and keep them out of the way.
- The client can hold the string in place against the nose with one hand, and hold the bead with the other. It is preferred that the client hold the string and bead if possible, but children and infirm adults will need the therapist to at least hold the bead. In contrast to the ROM OKN Pursuits 1 activity where the bead is moving, in this instance it is the bead that is held in position while the client’s head moves.
- The client is to start by facing forward, holding the string to the nose.
- The bead is held stationary and the head is moved in a repetitive manner in the sequences given below. The client maintains fixation on the bead while the therapist observes the targeting of the eyes. You can generally tell if the eyes are on target, but many people have difficulty maintaining good targeting with both eyes at some distances. Never scold a child/client if they cannot align both eyes on a target/bead, and do not tease them or comment. Simply move on to a different exercise. Consult your optometrist if you have questions.
- The following is a list of movement guidelines, therapists should explore all combinations and vary the activities at each session. Do a variety of these variations for perhaps 5-10 minutes. Never exceed what a client can comfortably achieve, but ensure the tasks are reasonably challenging. Keep the pace quick and move from one task to the next.
- Construct your activities using a combination of these ideas, again, keep the pace moving:
- Use an alternating patch for perhaps half of the time. So, if you do 4 minutes of this activity, do 1 minute with a patch on the left, then one minute with the patch on the right, then 2 minutes with no patch.
- Keep the bead steady and at the same distance throughout the activities.
- Move the head up and down. Be sure the client is not injured by moving the head too quickly. The speed goal is to achieve the fastest head movement while avoiding discomfort and injury. It’s ok if the bead goes out of reach for the eye, as in if it goes to high or too low to see anymore, this is actually preferred. Simply move the head in the reverse direction so the bead once again becomes visible. Continue moving through to the other side, moving the head up and down so the bead goes first first out of view, then returns back into view.
- Move the head side-to-side. As above, move the bead out of view, then back into view.
- Do head rotations in progressively wider circles. Be sure to keep the bead within view of the eye(s). Work in alternating directions, clockwise, then counter clockwise.
- Vary the speed. For example, you should move the head from the left side vision to the right in no more than perhaps 5 seconds. Try going progressively faster. Again, be careful and consult your optometrist should you feel uncomfortable with this activity.
- A laser pointer can be used to create a fixation spot at eye level on a near wall for a similar effect. The Brock String also provides a very strong stimulus in the string itself, giving the brain some else to work with to create the perception of depth and precision in two-eyed (binocular) targeting.
The Brock String posts include:
- Physiological Diplopia: When seeing double is correct.
- ROM OKR Pursuits 1
- ROM VOR Pursuits 2 – This post.
- Bug On String
- Basic Brock: Jumps Near Range
- Far Range
- Near-Far Rock
You should study all notes relating to Brock String activities prior to attempting them. Always follow the guidance of your vision care provider. Do not exceed what clients can comfortably tolerate.