The United States Census Bureau projects that by the year 2050, 20 percent of the United States population will be age 65 years or older1. Due to the rapid rate at which the population is aging, it is important for physical therapy institutions to educate their students on this special population. With this increase in percentage, it is very likely that the student will one day have patients of the geriatric population, therefore, it is important to be prepared.
There is a 30 to 50 percent decline in skeletal muscle mass from the ages 40 to 80, as well as a 3 percent annual decline in muscle functional capacity after the age of 602. Sarcopenia is an issue that physical therapists will be faced with when determining appropriate and necessary interventions. Sarcopenia can be defined as the age associated decline in skeletal muscle mass, which can lead to pain and fatigue that limits physical activity, further enhancing the decline of muscle mass3.
There are several factors that contribute to sarcopenia. Nutrition has found to be an important consideration with this disease. On average, as we age, there is a 25 percent decrease in caloric intake4. This can then lead to reduced protein intake and a decline in the amount of vitamin D levels, which both have been correlated with diminished muscle strength3.
Hormonal declines have been another factor that has been seen to be linked to muscle wasting3. In men, testosterone concentrations decrease as we age and has been associated with a decrease in muscle mass3 5. In women, it is suggested that estrogen is reduced and is a contributor to decreased muscle strength. Due to their anabolic effects on the musculoskeletal system, age related decreases in other hormones such as growth hormone and insulin growth factor-1 have been suggested as contributors to muscle wasting3. Studies have also shown that there are increased levels of myostatin as we age6. This increase in myostatin is correlated with reduced muscle mass3.
There appears to be physical changes in the morphology of the muscles and fatty infiltration of the muscle as we age. Muscle satellite cells can express adipocytic and a myocytic phenotype. It appears that as we age the muscle satellite cells express the adipocytic phenotype more often. There is also an increase in the amount of fat that is deposited in the muscle fiber as we age which is called intramyocellular lipid. This is believed to be from an increase of lipids due to reduced oxidative capabilities of the aging muscle fibers7.
The age-related loss of muscle mass results from loss of the fast and slow motor units, with an emphasis on the fast units. It has been studied that there is a decrease in the cross-sectional area of the type 2 muscle fibers and denervation of these muscles. The type 2 muscle fibers are converted to type 1 fibers which results in an increase in the type 1 fibers7. Therefore, this results in a decrease in the power generating abilities of the existing muscle fibers7. As we lose the ability to generate force with our muscles this may result in decrease in overall function as well. Similar to the previous though, some studies have examined the loss of power output as we age. Velocity at maximal power decreased 18 percent between the second decade and the fifth decade of life and by another 20 percent between the sixth and eighth decade8. However, other studies have reported declines in muscle power as much as 30 to 35 percent9.
For the muscle to fire correctly and efficiently there must be adequate functioning of the motor neurons. Age related neurodegeneration with the motor cortex, spinal cord, peripheral neurons and the neuromuscular junction can occur which contributes to skeletal muscle loss7. There are changes in the neuromuscular junction that cause a reduced number of terminals and synaptic vesicles10 11. There is also an increase in the number of neurotransmitters released and branching of terminal axons, which appear to be an adaptive feature of the nervous system to counteract the declining function12.
Another huge factor that physical therapist’s often seek to prevent and eliminate risk factors for is falls. Falls are very common in the elderly population with 1 in 3 falling at least once a year and the incidence of falls increases dramatically with age. The risk of falling more than doubles between 70 years of age and 80 years of age. Consequently, the falls lead to increased risk of fractures with more than half of the cases occurring at the hip joint. This can then lead to an increased fear of falling which results in further falling, avoiding daily activities, diminished social interaction, and decreased quality of life13.
While there are many age-related changes that can occur such as the ones previously mentioned, there are ways to combat these effects. Exercise is a key intervention in decreasing falls and increasing skeletal muscle in the aging adult population7 13. In a study with elderly men who took part in a 12-week resistance training program, participants were found to have increases of 11.4% in quadriceps muscle cross sectional area and greater than 100 percent in knee extensor torque14. Similar results have been found in women by other studies15. Interestingly, resistance exercise has been found to show benefits even when it is not routinely performed. Knee extensor strength has been shown to have sustained gains even after a period deconditioning following the conclusion of exercise16.
According to a 2016 systematic review, exercise was the most effective intervention in reducing falls in older adults in all practice settings. This review found that the most effective exercise programs were those that included combination of higher intensity and progressive balance exercises that were carried out in weight bearing positions, with lower extremity resistance training. Functional activities were also found to be effective. This included stair climbing, sitting to standing, flexibility and endurance methods of training13. Therefore, it is important for us as physical therapists to include functional related tasks with the appropriate type of activity related to the function.
In the community living elderly population, exercise programs were extremely effective at reducing falls. Programs like the Otago were highlighted in the 2016 review. The Otago is an individualized program of specific exercises that steadily increased lower extremity strength and balance. The sessions last about 30 minutes 3 times per week. The interventions include hip, knee, and ankle exercises with an ankle weight and balance exercises that are performed in various stances and various gait patterns. However, it was found that walking by itself was not an effective intervention. The Otago was found to be effective in those who were at higher risk for falling while Tai Chi was only effective in those who were at low risk for falling13. This suggests that different interventions may work better for different populations. Physical therapists should be cognizant of this when selecting interventions for their patients.
While exercise was shown to be effective in some, the evidence was mixed when analyzing the residents in long term care facilities. The 2016 review found that in some studies, when exercise was used as the sole intervention, there was not a reduction in falls. Due to the population of the long-term care facilities that these studies were performed in, it is suggested that the cognitive issues that these patients present with, may have impacted the results of the studies13. With this research in mind, physical therapists should be aware of factors like cognition, that may affect the patient’s treatment.
Polypharmacy is a common issue that exists within the geriatric community due to the high incidence of comorbidities. Polypharmacy has been defined as taking 5 or more medications17. It is estimated that 30 percent of the adults over the age of 65 fall under the category of polypharmacy18. While the geriatric population makes up a small amount of the population, they purchase one third of all prescriptions drugs and this number is projected to increase to 50 percent by 2040. Polypharmacy has been shown to increase the risk of adverse drugs events, avoidable hospitalizations, and health care cost17.
The overprescribing of medications can sometimes be caused by what is called a prescribing cascade. This is when one drug is taken which causes a side effect. A new drug will then be prescribed in order to counteract that side effect17. As one can see this can cause many medications to be prescribed. Uncoordinated care is another reason for polypharmacy17. Half of the people above the age of 65 have at least 3 medical diagnosis, and one-fifth have 5 or more19. The patients, therefore, can have the opportunity for more than one medical provider and more than one pharmacy. A lack of communication between the different providers and pharmacies may lead to negative drug interactions and the overprescribing of medications17.
An adverse drug event is an injury that results from the use of a medication. Older adults are more vulnerable to the adverse drug reactions due to the increased incidence of polypharmacy. Adverse drugs reactions are caused by drug to drug interactions and drug to disease interactions 17. The undesirable medication reactions can occur with patients who have a particular disease, such as a patient with dementia who takes an anticholinergic medication. This patient may express anticholinergic side effects as well as delirium17. There are risk factors that are associated with adverse drug events, such as age greater than 85, low body mass index, six or more chronic health conditions, 9 or more medications, and prior adverse drug reactions20. There are health care system factors that can negatively affect patients as well. These include multiple prescribers, multiple pharmacies, no regular review of medications, and poor communication among providers20. With these factors in mind, it is clearly important that the physical therapist reviews the patient’s medications at all times and be an advocate for the patient to prevent adverse effects as the ones mentioned above.
There are certain classes of medications that the physical therapist should be aware of when reviewing the patient’s medication list. Medications that have sedative or anticholinergic properties have been shown to increase the risk of falling in elderly patients. These medications are used heavily in the geriatric population for conditions like allergies, urinary incontinence, insomnia, anxiety, chronic obstructive pulmonary disease, depression, and gastrointestinal disorders. Tools like the Drug Burden Index have been used to evaluate to cumulative load that anticholinergics and sedatives have on the person. In a study with over 71 thousand participants it was found that the higher scores on the Drug Burden Index was associated with falls and is a practical tool for clinicians to use21.
Patient education is another key factor that needs to be addressed in the geriatric population. There are many resources out there that the physical therapist should be aware of. The Center for Disease Control (CDC) offers resources regarding the older adult population. They have created the Stopping Elderly Accidents, Deaths and Injuries (STEADI) program which is designed to offer healthcare providers who treat older adults’, resources to help their patients22. This program has three main parts that they find most important to the geriatric population. They are to screen the patient for fall risk, assess the modifiable risk factors, and intervene when possible by using effective clinical and community strategies. STEADI even offers educational resources such as brochures, podcasts and websites for the patients and their caregivers22. It is important as a student and practicing physical therapist to know where to go for resources when the patient has questions and the STEADI is an option for those resources.
Education about comorbid conditions is of high importance when treating the geriatric population. Studies have evaluated the effects of a diabetes education program. These studies found that with just using education as the intervention it can be effective in glycemic control23 24 25. The APTA recommends that the physical therapist educates the patient on weight control, eating a healthy diet, and a regular exercise program26.
From looking at the evidence above, an interdisciplinary approach would appear to be the best course of treatment for the geriatric population. There are several driving forces for working as an interprofessional team. These include the complexity around older adults, shared expertise, increased economic efficiencies, and formation of new policy27. However, there are negatives forces that hinder this interprofessional approach which includes, a lack of expertise in this field, lack of knowledge about other disciplines, existing academic infrastructure, and current reimbursement methods27. Even with these challenges, geriatrics is appearing to be a promising field where the interprofessional model should be promoted.
While there are many negative and non-modifiable factors that can occur as one ages, physical therapists are presented with an opportunity to really make a difference in the lives of the geriatric patients they have contact with. With the expertise the physical therapist develops in school and during practice, they can be the patient’s advocate and source of prevention for those modifiable risk factors that create barriers in the aging process. Therefore, it is important that the previous information and knowledge is included in any physical therapy educational program.
