The Art and Science of Teaching Orientation and Mobility 2013 Edition made Screen Readable for Blind and Visually Impaired Persons by Professor T K Bansal.

The diagonal cane technique is the first of two basic cane techniques used for independent travel. It enhances the student’s ability to travel independently through a familiar indoor environment. In the diagonal cane technique, the cane is held in a stationary fashion in front of the student to detect obstacles but does not assist in finding drop-offs (in which the level of the walking surface drops off to a lower level, such as on a descending stairway or from a curb into a street).

The second cane technique, the two-point-touch long cane technique (described in detail in Chapter 6), enables the student to travel in all types of situations, both familiar and unfamiliar. Using this advanced long cane technique, the student swings or sweeps the cane from side to side in such a way that the cane and tip preview the next foot placement of the student.

Either technique can be performed with various modifications that are appropriate for different travel situations and conditions. In the case of the diagonal cane technique, the student learns when to implement many or all of the diagonal cane procedures and is given enough time to practice each one sufficiently. The diagonal cane technique is useful in familiar indoor areas because, with it, the student detects many known objects or obstacles but does not adequately detect objects encountered outside the areas of cane protection or areas with drop-offs. Therefore, the student must learn these limitations and exercise caution when traveling even in familiar indoor areas, which may still change from moment to moment and day to day. For example, buckets and ladders can be temporarily placed along well-known hallways when construction work, painting, or even cleaning is being done. It would be easy for a student using the diagonal cane technique to place the cane under a ladder without contacting it and causing himself a serious injury.

The same indoor environment selected for lessons on self-protection techniques should suffice for lessons on the diagonal cane technique. uncluttered Hallways are excellent areas to introduce walking with a human guide while holding a cane and the initial diagonal cane lessons. As the student learns the skills, he travels through areas with more hallway furniture and through congested rooms to practice the skills while manipulating the cane in and around the obstacles.

5.4.1 Types of Grasps

(a) The Index Finger Grasp

The basic grasp for implementing the diagonal cane technique, the index finger grasp, is positioned as follows (see Figure 5.2):

Figure 5.2 The index finger grasp, the basic grasp for implementing the diagonal cane technique.

• The specialist faces the student, whose back is against a wall, and places the cane into the student’s dominant hand as if the student were shaking hands with the cane and with the midpoint of the grip flat against the center of the palm. The student places his index finger along the flat side with the other fingers and thumb wrapped around the grip.
• The student then rotates the wrist of his cane hand inward or toward him, so his palm is facing somewhat away from him, and places the cane diagonally across his body.
• The cane arm is then extended directly forward and away from the body at arm’s length. If the cane has a crook, it is positioned so that it encircles the knuckles and projects away from the student.
• The cane tip touches the floor approximately two inches beyond the widest portion of the body.

When held in the index finger grasp and when viewed from the front, the cane appears to be diagonal across the student’s body, extending from two inches beyond the shoulder of the dominant side to two inches beyond the opposite shoulder. In this position, the cane will act as a bumper for objects that are below the waist and in the student’s way as he moves through the environment. Many students have difficulty feeling that the cane is diagonal across the body and often think that the cane arm is positioned not forward but off to the dominant side. The specialist can help the student understand the relationship of the cane to his body by grasping the cane as it is held properly in position, allowing the student to let go of it entirely to run both hands along the cane shaft. The student then can feel the diagonal nature of the technique as he glides his hands along the shaft from the grip on the dominant side to the tip on the non-dominant side.

In addition, the specialist can have the student perform an isometric exercise in which the student, while the cane is in position, presses his cane hand toward his midline and against the resistance of the specialist's hand, which is braced against early in a stationary posture.

(b) The Thumb Grasp

The second diagonal cane grasp is called the thumb grasp. It is positioned as follows:

• All the fingers are wrapped around the grip with the thumb pointing down toward the tip and against the flat side of the grip.
• The hand and arm positions are the same as for the index finger grasp.
• The same exercises and procedures are used for both grasps.

(c) The Pencil Grasp

The third diagonal cane grasp is called the pencil grasp and is positioned as follows (see Figure 5.3):

Figure 5.3 The Pencil grasp used with the diagonal cane technique.

• The student grasps the cane with the grip placed between the thumb and the index finger. The thumb and index finger are wrapped around the grip, and the remaining fingers are cupped together and used to counterbalance the cane from underneath.
• The cane is pointed diagonally across the body with the tip touching the floor approximately two inches beyond the opposite shoulder. The cane hand is held either forward at arm's length from the student or forward with the arm bent at the elbow and with the elbow braced against the student's rib cage.

The student learns to feel the correct position in the elbow and shoulder of the dominant side by performing the following isometric exercise with the specialist: While in position, the student presses his cane hand toward his midline and against the specialist's hand, relaxes it, and repeats the procedure several times.

5.4.2 When to Use Each Grasp

The student needs to know when to use each grasp and how to manipulate the cane to assume any of the grasps in either hand. For example, he learns that the index finger grasp affords the best control when trailing a wall and that the thumb grasp is especially useful when walking Mo open spaces where there is little pedestrian traffic because the cane position is easily maintained and maneuvered. However, when many people are present, the pencil grasp may allow him to manipulate the cane in and around their feet gently as they stand or walk by. Ultimately, the student decides which cane grasp to use and when, since all students have their preferences for certain grasps.

5.4.3 Lesson Sequencing of the Diagonal Cane Technique

The sequence of the lessons should move from simple motor skills to more complex skills. One skill should be learned well before another is added. Therefore, the specialist does not introduce all the grasps in the same lesson but gives the student time to practice each sufficiently in either hand and with the tip of the cane on or off the floor. While using any of the three grasps, the student keeps his free arm relaxed at his side or in the upper hand and forearm technique. The specialist observes the free arm to ensure that over time it becomes relaxed while the student moves into open spaces. At first, the student will probably hold the free arm stiffly as he concentrates on positioning the cane hand and arm. As he learns the skills, his free arm should relax and swing normally at his side. Lessons progress from travel in open spaces to trailing and then to a mix of each similar to the sequence described for self-protection techniques in Chapter 4. (For information on the time frame for learning this and other techniques, please refer back to Chapter 1.)

5.4.4 Walking into Open Spaces and Changing Grasps

The student learns to walk forward into open spaces maintaining the proper positioning of each grasp while following the specialist’s voice. Before he learns another grasp, he learns one grasp well with one hand and then learns to use it with the other hand. Finally, he learns to switch grasps in either hand while in motion. When the cane grasps are switched within each hand and between hands, the cane is not lifted off the ground for more than one or two inches. The cane is allowed to glide along the ground and later to remain lifted off the ground for one or two inches while in motion. By the end of this mini-unit of instruction, the student should be able to walk down a hallway and change grasps at will.

5.4.5 Contacting and Examining Objects

Whenever the student makes contact with a wall at the end of a route and when using the diagonal long cane technique, he should follow this procedure:

• While using either the index or thumb grasps, he positions the cane tip up against the wall while rotating his cane hand inward (if using the pencil grasp, he simply walks up to the wall as the tip rests against the baseboard).
• He approaches the wall, so the cane shaft becomes vertical to the ground and is at his midline.
• He then turns around and places his back to the wall to indicate he has completed the route.

When the student contacts an object that is below the cane grip, he follows the same procedure but takes his free hand and runs it down the shaft to contact and then explore the object. To avoid losing his balance while exploring, he squats without leaning forward as he runs his hand down the shaft to find the object. After he learns to find and explore objects to identify them, the student is encouraged to explore and identify objects only, when necessary, because this practice slows down his travel and diverts his attention from other more important environmental cues in more advanced travel situations later in the program.

5.4.6 Trailing a Wall While Using the Diagonal Technique

After the student learns to use diagonal cane skills while walking into open spaces, he learns to use each grasp while trailing a wall line (see Figure 5.4).

Figure 5.4 Trailing a wall while practicing the index finger grasp with the diagonal cane technique.

Each grasp is practiced first while the cane is in the student's dominant hand and then in the non-dominant hand. Therefore, the student walks along the wall with the cane in the dominant hand and the cane tip against the wall just above the baseboard and returns to the starting point with the specialist using the human guide technique. The student repeats this procedure several times until the specialist notes that he has attained the skill.

After many one-way trips along the wall in this manner with the cane in the dominant hand, the specialist introduces the skill using the non-dominant hand. The student is again brought back to the starting point using the human guide technique after each one-way trip. The student then practices walking along the wall making a round-trip back and forth with the cane in the appropriate hand each time. (Sidebar 5.1 presents an example of a lesson on using the diagonal cane technique while trailing a wall.)

SIDEBAR 5.1

Case Study: Learning Diagonal Cane Technique While Trailing

Gloria is teaching her student, Luis, how to use the diagonal cane technique while trailing along a wall. Luis is 32 years old, adventitiously blind, and has been residing for several months in a residential rehabilitation center for the blind. Luis has already learned how to hold and maintain the cane in position and walk out into open spaces.

Gloria: Luis, today we are going to learn how to trail a wall while using the diagonal cane technique. Please turn so your right shoulder is slightly touching the wall. Good, now place the cane in your left hand and the diagonal cane position. Great, now position yourself so your shoulder is no longer touching the wall and your cane tip is lightly touching the baseboard of the wall and just above the ground. Excellent! Now that you and your cane are in position, I would like you to walk along this wall while maintaining this position throughout.

If Luis had had difficulty with his cane and body positions, Gloria might have gently positioned the various aspects of the technique by touching the hand or shoulder or the cane itself.

As her student begins to walk, Gloria monitors his cane, hand, and shoulder positions. She also provides verbal and tactile feedback along with repositioning as she walks alongside her student. If Luis were to begin to drift away from the wall, Gloria would let him bump into her, shoulder to shoulder, so that he could feel himself drifting. Gloria knows that if she were to wait until the end of the run to give feedback, her student might engrain the incorrect skill, making it more difficult to correct.

After they run the route, Gloria uses a human guide and takes him back to the starting point to practice the skill along the same side. They continue until Luis has learned to perform the skill matter-of-factly. Once the skill is learned while trailing along one side, the team can turn their attention to learning the skill along the other side, following the same procedure. 

End of the sidebar

(a) Trailing a Wall with No Objects or Openings

To trail a wall in which there are no openings or protruding objects, the student stands parallel to the wall with the nondominant shoulder nearly touching the wall. He holds the cane in the dominant hand using the index finger grasp with the tip touching the wall and slightly off the floor. The student maintains the proper position while trailing along the wall with the cane tip, preferably using a light touch. He may choose to keep his free arm at his side or in his pocket, bent at the elbow, and across the small of his back, or in the upper hand and forearm position.

(b) Trailing across Doorways or Corridors

In trailing across openings in a wall, such as doorways or corridors, when the student's cane tip contacts a doorjamb or end of a wall line, it is projected forward and parallel to the wall as the student moves forward across the opening. The tip will contact the opposite doorjamb or wall after the student's cane has crossed the opening. Care is taken not to allow the tip to be pushed into the opening, so the cane does not bang into closed doors, trip anyone in the doorway or corridor, or get hung up in the opening. The student learns to avoid these problems by performing a slight arching motion away from and back toward the wall as the tip crosses the opening. Finally, the student learns to distinguish doorways from corridors by the length and time it takes to make the crossing: doorway crossings are generally shorter than corridor crossings.