2. Ambulatory devices

There are many ambulatory devices developed to suit diverse presentations from difference medical or surgical conditions and these include parallel bar, walker, crutches and cane. Each of the ambulatory device has advantages and disadvantages that enhance their prescription and usage. Therefore, clinicians need to have a good understanding of these ambulatory devices to be able to recommend

Prescription of ambulatory device is determined by the user's anthropometric parameters (body weight, height and body mass index), user's abilities (skill), user's needs and environment. Other factors that influence the prescription of ambulatory devices include; weight bearing status, the degree of support or assistance the device can offer, the coordination of the user, range of motion available at the involved joints, balance, stability, strength, and general condition of the user.

There are also body functions involved in determining user's capacity to use an ambulatory device, these are cognitive function, judgment, vision, vestibular function, upper body strength, physical endurance. Depending on severity, impairments in any of these functions could make it impossible for a user to safely use a device. The prescription of any ambulatory device should specify the device most likely

to maximize the user's function; the individual's goals and personal preferences must also be considered. Physiotherapists are licensed and help with the fitting and proper use of ambulatory device while other health practitioners can also recommend ambulatory devices. All ambulatory devices are made in different height and so user must be fitted in order to obtain the correct ambulatory device height [6]. The functions of ambulatory devices when properly use includes the following:

• Provides assist forward, backward and lateral movements: users of an ambulatory device can walk in any direction with and within the device.

• Helps to increase balance, stability and coordination of the users: there is increase balance due to the increase in the base of support provided by the

• Helps to reduce weight bearing on the affected lower limb: use of ambulatory devices result in the upper limbs sharing weight bearing with the affected lower limbs, thereby reducing the weight of the body of user being borne on

• Helps to increase confidence of the users: the user can move independently

the ideal ambulatory device for the user [3, 10].

Prosthesis

ambulatory devices (Figure 1).

without or with little manual assistance.

Increase of the base of support for a user of ambulatory device (crutches).

the affected lower limbs.

Figure 1.

60

Ambulatory devices are aids made of durable and non-malleable materials for assistance during walking and standing. The main function of ambulatory device is to reduce the amount of weight bearing on the weak (or affected) lower limb or totally eliminate weight from the lower limb by transmitting the body weight from the upper limb to the floor through the ambulatory device [8]. Weight bearing status of ambulatory device user is the amount of weight the user put on the weak (or affected) lower limb during ambulation. The weight bearing status can be measured in grades or percentages. The amount of weight bearing on the weak (or affected) lower limb is determined by the user medical history, weight bearing capacity as can be tolerated and functional ability of the weak (or affected) lower limb [11]. The weight bearing status available among ambulatory device users (apart from cane) are as described below:

Non-weight bearing (NWB): the affected lower limb will not touch the floor during ambulation (i.e., no weight is borne on the affected lower limb) [11]. The percentage of body weight transmitted to the floor, through the affected lower limb is zero (0)% (Figure 2).

Touch down weight bearing (TDWB): this is also known as toe touch weight bearing (TTWB). Here, the foot or the toes touch the floor but no weight is transmitted to the floor through the affected lower limb involved. Thus, the percentage of body weight transmitted to the floor, through the affected lower limb is also zero (0)% (Figure 3).

Partial weight bearing (PWB): here, a little amount of weight is transmitted to the floor through the affected lower limb. The percentage of body weight transmitted to the floor can range between 1 and 50% [11]. During the training stage, two body weighing machines/apparatus can be used to accurately determine the percentage body that may borne on the affected lower limb (Figure 4).

Weight bearing as tolerated (WBT): the user of the ambulatory device determines the amount of weight to bear on the affected/involved lower limb. The weight bearing status is totally dependent on the individual ambulatory device user and the percentage of body weight transmitted to the floor can range from 50 to 100% [11].

Full weight bearing (FWB): the affected/involved lower limb can bear the total weight of the body. The percentage of body weight transmitted to the floor through the affected lower limb can be 100% [11]. This type of weight bearing status is used to build confidence with the ambulatory device user.

#### Figure 2.

Non-weight bearing (NWB) on the right lower limb. The non-weight bearing limb is not touching the floor.

3. Categories of ambulatory device

Ambulatory Devices: Assessment and Prescription DOI: http://dx.doi.org/10.5772/intechopen.89886

4.1 Description and components of parallel bar

the needs of the user.

4. Parallel bar

63

Figure 4.

Ambulatory devices can be group into categories depending on the basic design. When arranged in the level of stability of the ambulatory device the progression is parallel bar, walker, crutches and cane. Each of the categories of the ambulatory device is then redesign and modify to different styles and types to specifically meet

Partial weight bearing (PWB) or weight bearing as tolerated (WBT) on the right lower limb. The weight the

reference lower limb bear is decided by the amount of weight that can be tolerated.

Parallel bar are fixed apparatus with a pair of horizontal bars on vertical posts used for standing and ambulatory training (Figure 5). It is a medical ambulatory device with two parallel horizontal bars on fixed four legs; the user holds the horizontal bars at wrist height and move forward, backward and sideways, usually

#### Figure 3.

Touch down weight bearing (TDWB) on the right lower limb. The reference lower limb is only touching the floor but not bearing weight.

Ambulatory Devices: Assessment and Prescription DOI: http://dx.doi.org/10.5772/intechopen.89886

#### Figure 4.

Partial weight bearing (PWB) or weight bearing as tolerated (WBT) on the right lower limb. The weight the reference lower limb bear is decided by the amount of weight that can be tolerated.

#### 3. Categories of ambulatory device

Ambulatory devices can be group into categories depending on the basic design. When arranged in the level of stability of the ambulatory device the progression is parallel bar, walker, crutches and cane. Each of the categories of the ambulatory device is then redesign and modify to different styles and types to specifically meet the needs of the user.

#### 4. Parallel bar

#### 4.1 Description and components of parallel bar

Parallel bar are fixed apparatus with a pair of horizontal bars on vertical posts used for standing and ambulatory training (Figure 5). It is a medical ambulatory device with two parallel horizontal bars on fixed four legs; the user holds the horizontal bars at wrist height and move forward, backward and sideways, usually

Figure 3.

62

Figure 2.

Prosthesis

floor but not bearing weight.

Touch down weight bearing (TDWB) on the right lower limb. The reference lower limb is only touching the

Non-weight bearing (NWB) on the right lower limb. The non-weight bearing limb is not touching the floor.

3. It is expensive compared to other ambulatory devices: it is not readily made available for home use because the financial implication involved in building it. Thus, its usage usually requires moving the patient (users) to the facility

Parallel bars are usually adjustable, the heights of the bars are adjusted to fit the user. The adjustment is estimated base on the user's height. The bars should be at the level of the greater trochanter of the user and the elbow joint should be able to flex to about 20 or 30 degrees when the user grips the horizontal bars. Further adjustment of the heights of the bars is made, with the view to fit the parallel bars to the user's height, immediately the user is position in standing position, where there is need. Usually the adjustment of the parallel bar is fixed at two- and half-inch interval or less depending on the manufacturer and the user (adult or

Prior to ambulation using the parallel bar, the following safety and precautions

• The stability of the parallel bar should be checked. All the vertical posts (limbs)

• All the push buttons for height adjustment should be visible and at the same

• The handgrips on the horizontal bars should be attached sturdily and not move

• There should be no loose component (screw, nuts or bolt) in the parallel bar.

Also, the following instructions should be given to the users before they are

• Users should maintain good posture (hyper flexion of the head, neck and trunk

Users of parallel bars first need to learn how to stand using the parallel bar. The user uses one of the upper limbs to hold one bars of the parallel bar (for stability and balance) and the other upper limb to assist in standing by pushing up on the seat (Figure 6A). Clinicians can assist the user into standing position from sitting by assisting the user from the axilla region. Immediately the user is almost standing user change the position of the upper limb that was on the seat to the other bar of the parallel bars (Figure 6B). User stands upright within the walker, adjusting the

When siting from standing using the parallel bar, the user follow the reverse pattern of standing. From upright standing within the parallel bar, the user place

of the parallel bar should be fixed, stabilized and immovable.

• No dents, cracks or any irregularities on the parallel bar.

• Users should hold the horizontal bars firmly.

upper limb and lower limb till the user is balance.

(i.e., hospital).

4.4 Fitting of parallel bar

4.5 Instruction on the use of parallel bar

Ambulatory Devices: Assessment and Prescription DOI: http://dx.doi.org/10.5772/intechopen.89886

pediatric).

should be checked.

height level.

when pressure applied.

positioned between the parallel bars:

should be avoided).

65

Figure 5. Parallel bar fixed together for stability. There are knobs on the vertical poles for adjusting the height.

in front of a standing mirror. Each of the horizontal bars is mounted on two adjustable vertical posts to allow for easy adjustment of height of the parallel in accordance with the anthropometric parameters of the users. The entire horizontal bars form the handgrip for the users. The vertical posts are fixed to the floor or joined together for stability of the parallel bar. The horizontal bars are about 18 inches apart; and are set at the same height by the vertical posts which are about 11 feet (340 cm) long. Pediatric parallel bars are also available with adjustable height. The horizontal bars are usually made of wood; while the vertical posts are made of different materials such as stainless steel, aluminum steel or iron. The material used to manufacture the parallel bar determines the weight, durability, cost, strength, comfort and safety.
