One of the activity outputs described in Chapter 2 (see Figure 2-7) is manipulation. At the most basic level, manipulation refers to those activities that we normally accomplish using the upper extremities, particularly the fingers and hand. Many types of “manipulation” are required to use assistive devices, especially those that are electronically controlled. For example, keys must be pressed for computer entry, joysticks controlled for powered mobility, and switches activated for communication devices. We have discussed this type of manipulation in previous chapters, and we exclude it from the general discussion of manipulation in this chapter. In this chapter, we describe gross motor manipulation as reaching, grasping/releasing, lifting, carrying, and coordination of movements such as pushing, pulling, and turning. Fine motor manipulation includes pinch, point, and dexterity of finger movements. The end goal of the integration of these manipulation components is a person’s actions in daily and life activities. For example, activities such as handwriting, food preparation, eating, reaching, using controls in the environment such as door handles and elevator buttons, and appliance control depend on manipulation of physical objects. These types of activities and the technology that supports them are our focus in this chapter.

Figure 14-1 is a characterization of assistive technology devices used for manipulation. As in many other areas of assistive technology application, we can provide manipulative aids that are either alternative (a different method of doing the same task) or augmentative (assistance in doing the task in the same manner as it is normally done). For manipulation, we can also distinguish devices as being either specific purpose or general purpose. Specific-purpose manipulation devices are designed for only one task, whereas general-purpose manipulation devices serve two or more manipulative activities (see Chapter 1). For example, an augmentative, specific-purpose approach to eating may include a modified fork with an enlarged handle. An alternative, special-purpose apparatus for eating is an electromechanical device that lifts food off the plate and up to mouth level when a switch is pressed. A hand splint that allows gripping of any utensil serves as a general-purpose augmentative aid, since it can be used to hold a fork for eating or a pen for writing. In this chapter we discuss all four categories of assistive technologies for manipulation shown in Figure 14-1.

The variety and choice of technology to assist with elements of manipulation have expanded greatly over the past several years. Often a commercially available tool or appliance will work very well for an individual with a disability to assist with manipulation. A commercially available gardening tool with an enlarged handle is an example of universal design, as described in Chapter 1, because it is useful by a wide range of individuals. Many implements for activities such as cooking and gardening are commercially available with enlarged or ergonomically designed handles. In a similar fashion, manufacturers are producing implements with telescoping or long handles. Follow the device selection guidelines described in Chapter 2 to identify devices that will assist a client with many manipulation tasks. Modification of implements they currently own or the purchase of commercially available implements is frequently a simple means to assist with manipulation.

Manipulation

The definition of manipulation that was given at the beginning of this chapter suggested that it involves what we do with our upper extremities. Generally, it involves gross motor functions (larger and more forceful movement and function) and fine motor functions (smaller and more delicate movements). Fine motor coordination is considered to be “the smooth and harmonious action of groups of muscles working together to produce a desired motion.”⁶ Let’s look at the activity of dressing to illustrate gross and fine motor actions. Gross shoulder movements are needed to reach overhead, behind the back, across the midline of the body, and below the waist for lower extremity dressing. Elbow range of motion is needed to assist with reaching. Grasp and release are needed to grab and hold clothes while putting them on and taking them off. Strength is needed for grasp/release as well as to pull clothing up or down, on or off. Fine motor movements are necessary to use zippers, button and unbutton, tie shoelaces, and use fasteners behind the body (e.g., buttons or the hook and eye of a waistband). Gross motor functions important here include reaching; grasping/releasing an object; lifting and carrying an object; and actions such as pushing, pulling, and turning an object or control.

Manipulation can be affected by conditions that affect range of motion including those that limit strength, cause pain, or result in flexible or fixed deformities. Strength is also affected by conditions that result in pain or changes in muscle function. Dexterity and fine motor coordination can be affected by tremor and imbalances of muscle tone (e.g., hyper- or hypotonus). Examples of musculoskeletal conditions that affect manipulation include rheumatoid arthritis, osteoporosis, fracture, and amputation. Neuromuscular conditions that affect manipulation include cerebral palsy, spinal cord injury, stroke, traumatic brain injury, and progressive disorders such as amyotrophic lateral sclerosis, multiple sclerosis, and muscular dystrophy. Manipulation can also be affected by general conditions such as frailty and morbid obesity, primarily through loss of strength.

Low-technology aids for manipulation

In Chapter 1 we define low-technology aids as inexpensive, simple to make, and easy to obtain. Many manipulative aids fall into the low-technology category. We group these aids into general- and specific-purpose devices. Within specific-purpose devices, we categorize devices according to the major performance areas of the Human Activity Assistive Technology (HAAT) model: self-care, work or school, and play or leisure. The examples and other aids to daily living are available from many sources, including home health stores and online and mail-order catalogs.*

General-Purpose Aids

To be classified as general purpose, a manipulation aid must serve more than one need. Three general purpose aids are described here because they are commonly found in most environments: mouthsticks, head pointers, and reachers. The first two of these are often used as control enhancers in conjunction with control interfaces. Head pointers and mouthsticks are discussed in Chapter 5, including their use as control enhancers for activating control interfaces. Both mouthsticks and head pointers are used for direct manipulation. Turning pages is often accomplished with a mouthstick or a head pointer used in conjunction with a book or magazine mounted on a simple stand. A ballpoint pen tip or a pencil can also be attached to a mouthstick for writing. Additional attachments include a pincher that is opened or closed by tongue action and a suction cup end that can be used to grip objects (e.g., a page) by sucking on the end of the mouthstick. Many tasks require sliding objects (e.g., paper, pens) around on a desk or table. Both mouthsticks and head pointers can be used for this task. Mouthsticks or head pointers can also be used for such functions as dialing a telephone, typing, and turning lights on and off.

Many individuals need to extend their physical range. Often the need for extended range is a result of being seated in a wheelchair and wanting to reach an object on a counter or in a cabinet. In other cases it is a need to reach an object on the floor when bending is difficult or stability is poor. Reaching to the floor or in a forward direction is difficult following a hip replacement or a hip fracture when the individual has limitations in hip movements. In all these cases, reachers can be useful. A reacher consists of a handle grip that is used to control the jaws of the reacher in order to grasp an object. The grasp required to activate the grip may be of several types: squeeze with the whole hand, pistol grip with all the fingers, or trigger with the index finger. Overall length varies from 24 to 36 inches, and some models fold for ease of carrying. The gripper portion of the reacher may be circular for ease of gripping cans or pincher-like for picking up smaller objects. Rubber or other nonslip materials are often used for grippers on reachers. Reachers can be used to manipulate many objects, including food (e.g., cans, packages), cooking utensils (e.g., pans, pots, plates, dishes), office objects (e.g., paper, books, magazines), and recreational or leisure objects (e.g., books, tapes, CDs).

Reachers are used in many ways to manipulate different objects. They can act in similar ways to head pointers and sticks to push or pull objects into a space that is usable by the individual. Reaching devices can assist with activities such as dressing, hygiene, and other self-care activities and household activities (i.e., any activity that requires grasp and retention of an object that is outside of the individual’s reach). Because a reaching device extends the length of the arm, it also extends the length of the lever arm, resulting in increased force required to lift the object. As an experiment, try lifting a book and holding it close to your body. Hold it in that position for about 30 seconds. Sense its weight. Now hold the book at arm’s length. Hold it in this position for 30 seconds. Notice the difference in the sensation of weight. The book feels like it weighs much more when held away from the body; more force is required to hold it. Keep this consideration in mind when encouraging a client to use a reacher.

Specific-purpose electromechanical aids for manipulation

There are two primary manipulative tasks for which electromechanical devices have been specifically designed and for which there are commercially available products: (1) feeding and (2) page turning. We discuss these specific-purpose alternative manipulation devices in this section.

Electrically Powered Feeders

One area of human activity in which independence is highly desirable is eating. Anyone who has been unable to feed himself (even for a brief period) knows the frustration of looking at one type of food on the plate and being fed another (e.g., expecting peas and getting potatoes). Being fed by another person can also create a feeling of dependency, and lack of independence in eating is often equated with childlike behavior. None of these stereotypes is accurate, and most persons who are fed by an attendant maintain control over the situation through direction of the attendant’s actions. Nevertheless, many people would prefer to feed themselves if it were possible. Electromechanical feeders make this an option even for individuals who have very little motor control.

Use of an electrically powered feeder requires that the individual be able to control two separate functions. The first of these is location of the particular type of food that is to be eaten, and the second is picking up the food and moving it to mouth level. Currently available feeders require that the human operator be able to take food off a spoon, chew it, and swallow it safely. These requirements eliminate a large number of persons, but there are many who only lack the ability to pick up the food and get it to their mouths. It is this group for whom feeders are most beneficial.

The most commonly available feeder is the Winsford Feeder®,* which is marketed by several mail order equipment companies. This feeder is illustrated in Figure 14-6. This feeder has rechargeable batteries that are used to power it at many different settings. It has an adjustable height base that can accommodate varying spoon height requirements. A chin-activated dual switch is mounted on a long, solid wire. When it is pushed in one direction, plate rotation occurs; and when it is pushed in the opposite direction, food is pushed onto the spoon and elevated to mouth level. The device can also be controlled by a hand or foot adaptation. Other dual switches or two single switches may be adapted to work with this feeder. Although the device is portable, it does take considerable space on a table so its use in community settings such as restaurants may be limited.

Another dining device is the Meal Buddy, which incorporates a robotic arm to scoop food from the bowl and transport it to the consumer. The arm is activated with a single switch. A sip-n-puff option is available. The system includes three bowls for different food types or courses. It is also portable but, as with the Winsford Feeder®, it takes up considerable space on a table. The primary safety consideration of these devices is the avoidance of the spoon hitting the user in the face.

These feeders require assistance from another person for setup of the device and preparation of the food. Food must be prepared so that it is either mashed or pureed or cut into bite-size pieces. Liquids such as soup are difficult to consume using these systems. In addition to the space they take on a table, the devices are not always reliable, causing unwanted attention to the user if food falls off the spoon onto their clothing or the table. In addition, because the device is unusual and large, the novelty of this method of eating might bring unwanted attention. So, while the device affords independent eating, once setup has taken place, its use might only be acceptable to the user in his own home. In the community or another social setting, the individual may choose to receive assistance from another person. This influence of location is an example of the social context from the HAAT model as well as resource allocation, both discussed in Chapter 2.

Electrically Powered Page Turners

Access to books, magazines, and other reading material is important for the acquisition of information for school, work, or leisure. There are many individuals with disabilities who are able to read, but who cannot physically manipulate the pages of the reading material. There are several approaches that can be used to assist these individuals. A book holder and mouthstick (see the section on low-tech aids in this chapter) allow independence in page turning for some persons. The major limitation of this approach is the requirement that the book be set up by an aide and properly positioned for both visual and physical access. This method also requires a high degree of head control and the ability to hold a mouthstick. A mechanical head pointer eliminates the last requirement, but can result in neck fatigue if the user reads for a prolonged time.

Talking books, such as those made available for the blind, can also provide an alternative to physically manipulating pages. These are discussed in Chapter 8. Using a simple environmental control unit, a person with physical limitations can control the tape recorder and obtain access to the talking book at her own speed. Another approach is the use of books on computer disks. These can be loaded into a word processor, and the person needing access can use standard computer adaptations to turn the pages, scan through the material, find key words, and so on. This approach is also used by persons who have low vision or are blind, and we discuss it in Chapter 8. Both talking books and computer-based reading suffer from the limitation that not all reading material is available in these formats.

The recent advent of e-readers and tablet computers has significantly enhanced access to books and other reading materials. The user can download reading material directly to the device or through a computer. They can be positioned on a stand to relieve the need to hold the device. Most include a touch screen as a method of turning the pages, which is completed in a very intuitive manner. Others have buttons to advance the pages. A mouthstick or head pointer can be used to turn the pages, providing the device is well stabilized. Many of these products have options to change font size. As these products become more available, add-ons are being developed that make them more accessible. For example Airturn (www.airturn.com) has a wireless hands-free device that allows the user to change pages through the use of a foot switch. Some of the devices have text-to-speech applications, although with varying reliability. Apple products can use the VoiceOver feature that is part of the Mac operating system. Others have proprietary software, which is inconsistently used by publishers of the material offered by the device manufacturer. A major limitation is that many of these devices do not have USB ports, which limits their modification through the connection to switches. However, third party applications are available that enable modifications to allow switch access.

A final alternative is an electrically powered page turner. From a manipulative point of view, page turning of print material requires two primary actions: (1) separating the page to be turned from the other pages and (2) physically moving the page from one side to the other (forward or backward). Additional useful but not essential features include scanning a number of pages, turning to a specific page, and locating a bookmark and turning to that page. Turning a single page is the most difficult for page turners, and its success for any page turner is a major indicator of the quality of the unit. Because reading materials differ widely in size, binding (e.g., uniform, spiral, loose leaf), and paper types (e.g., rough, slick, newsprint), it is important to evaluate any individual page turner with reading materials that vary in size, paper type, and binding style. Once the page to be turned is successfully isolated, the page turner must move it to the opposite side of the book or magazine.

The Gewa page turner * (Figure 14-7) uses a rotating roller to separate pages from each other and then moves the entire roller from one side of the book or magazine to the other after the page has been separated. The standard control for the Gewa is a four-direction joystick. Two joystick directions cause roller rotation either clockwise or counterclockwise, and the other two cause the roller to move forward or backward. Any other four-switch control interface can also be used. An additional accessory for the Gewa is a scanning selection method in which a single switch is used to select one of the four control functions as they are presented in sequence. The display of functions consists of small LED indicators, with each labeled function corresponding to one joystick direction.