Muscular dystrophy causes progressive weakness and loss of muscle mass due to abnormal gene mutations. These mutations negatively affect the proteins needed to build healthy muscle (Newman, 2017). There are six different forms of muscular dystrophy (see Figure 4.3). Each type has varying degrees of severity and age of onset. Some people with muscular dystrophy has an average life span with mild symptoms that progress very slowly; others experience sudden and severe muscle weakness and wasting.
More than 50,000 Americans are affected by one of the nine types of muscular dystrophy (Newman, 2017). The frequency of each form listed in Figure 4.3 shows Duchenne muscular dystrophy presenting at a significantly higher percentage than other forms. Some estimates suggest that Duchenne muscular dystrophy affects roughly one in 3,500 boys (Henderson, 2017) worldwide. The effects of each type of muscular dystrophy depend on the affected muscles and the age of symptom onset. Some forms of muscular dystrophy are passed from parents to offspring through the X chromosome, which means that boys are affected more frequently.
Children diagnosed with Duchenne muscular dystrophy present symptoms early in age, but these can also appear later in life. Symptoms include difficulty in learning how to crawl and speak. As the children mature, they will present with difficulty in standing and develop a waddling gait (Henderson, 2017). During preadolescence, they will exhibit progressive postural deformities and increased muscle weakness as their muscle fibers continuously weaken.
The nonuniform weakening of specific muscle fibers (think of a cable with many wires, each wire is akin to a muscle fiber) results in generalized weakness and loss of coordinated movements. Those affected by Duchenne muscular dystrophy often walk with a waddle, fall frequently, have trouble getting up from the floor or a chair, or out of bed. During this phase,
Figure 4.3 Types of Muscular Dystrophy
Each form of muscular dystrophy affects different muscle groups and will impede different activities of daily living. Of all forms, Duchenne and Becker have the most profound effects.
Source: Image created by Dafne Odette.
Figure 4.4 Trapeze Bar
Placing a trapeze bar over the bed assists the person to use additional muscles to sit up and get out of the bed.
Source: Image created by Dafne Odette.
it is crucial to assure the child’s health and safety by removing or lessening the effect of sharp corners, removal of glass surfaces, and omit area rugs not completely affixed to the floor. A case-by-case assessment of each environment for hazards will determine the best design approaches. Remember that the first rule of a health care designer is not to draw attention to the health condition.
Most boys affected by Duchenne muscular dystrophy will lose the ability to walk by 12 years of age. They will further develop respiratory or cardiac complications, which will lead to premature death, often in their twenties (Lim et al., 2017). Very little can be done for a person affected by Duchenne muscular dystrophy. However, a health care designer can assist in the rehabilitative process by providing elements in the home environment that will help maintain muscle strength and encourage flexibility. For example, a Trapeze bar over the bed can help the person sit up as the disease progresses. The designer including a trapeze bar (see Figure 4.4) in a design will need to ensure proper securing of the bar to a support beam.
The most common form of muscular dystrophy in adults is called myotonic muscular dystrophy (also called Steinert’s disease). This form of muscular dystrophy affects men and women equally and can occur during early childhood to adulthood. In rare cases, the condition will appear in newborns. The name “myotonic” refers to the symptom myotonia, which is a prolonged spasm or stiffening of a muscle after use. This symptom becomes worse in cold conditions. What is unique about myotonic muscular dystrophy is that muscle weakness affects the central nervous system, which includes the heart, gastrointestinal tract, eyes, and hormone-producing glands. Myotonic muscular dystrophy is a slow progressing version of muscular dystrophy; however, those affected by the condition often have a shorter life expectancy.
Becker muscular dystrophy is a milder form of Duchenne muscular dystrophy with symptoms generally present between the ages two and sixteen. Becker muscular dystrophy progresses slowly and affects roughly 1 in 30,000 males. Those affected by Becker muscular dystrophy often walk on their tiptoes, fall a lot, have difficulty getting up from the bed, chair, or floor, and tend to have painful muscle cramping.
In this section, only four of the nine types of muscular dystrophy have been discussed. The most significant difference between the different types is the age on onset, speed of progression, and areas affected. The health care designer must know that Duchenne muscular dystrophy is the most common form that affects young boys. By understanding the basic physiology of the health condition, the health care designer can develop spaces based on the progressive weakening of the specific muscle groups.