Mobilization and Exercise: Testing and Training

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Mobilization and Exercise

Testing and Training

Elizabeth Dean and Scotty Butcher

Key Terms

This chapter describes the principles and practices for exploiting the preventive, acute, and long-term effects of mobilization, exercise, and training. Mobilization and exercise are prescribed to elicit whichever of these distinct effects is indicated. They are prescribed on the basis of their indications, contraindications, and potential side effects for a given individual. Exercise to exploit each of these effects can be prescribed to address limitations in specific organ systems, as well as augment activity ability and participation. Chapters 24 and 25 expand on these topics, describing special considerations for patient populations with an emphasis on targeting exercise testing and prescription for training based on people with conditions rather than for the condition(s) a patient has.

Pre-exercise Test Evaluation

In addition to exercise test indications and contraindications (see next section), a detailed history and examination need to be conducted to determine the appropriateness of test selection, to quantify the relative risk associated with exercise testing, and to determine the level of supervision required. This includes the usual medical and surgical histories to define the types of pathology a patient may have and that may limit his or her exercise capacity. In addition, all medications need to be considered. Which medications impact exercise performance either positively or adversely? Which medications may need to be taken prophylactically? What medications was the patient taking on previous exercise tests? Are these being taken this time? How will this affect the current exercise test results in terms of their comparison? Can medications be withheld? (And should they be?) When is the patient exercising in relation to the timing of medication administration? How might this affect exercise performance? Is this different from a previous test? What about time of day? Does this differ from the time of day when a previous test was performed? Cumulative fatigue and/or discomfort or pain over the course of a day are often reported by patients with certain chronic conditions, thus warranting the establishment of a standard time of day for testing. Other issues must be considered. For instance, how well did the patient sleep last night? How well hydrated is the patient? What and when was the most recent meal? Is the patient a smoker? If so, when was the last cigarette smoked? Additional external factors such as the ambient temperature of the test location and the presence of noise, distraction, and disruption need to be controlled.

Pre-exercise Screening for Minimizing Cardiovascular Risk During Testing

Exercise testing can pose a risk to the patient, so exercise testing must have clear indications, and any contraindications must be ruled out. On the other hand, earlier guidelines for exercise testing in patients, particularly those with cardiac conditions, were too conservative.1 Patients can be exercised aggressively provided that the indications are based on a comprehensive assessment and a judiciously selected exercise test and protocol and provided that the patient is appropriately monitored throughout testing. The American College of Sports Medicine (ACSM)2 has developed an algorithm (Figure 19-1, A) to determine the risk for cardiovascular events during exercise testing (Table 19-1) as well as guidelines for test selection and level of supervision required based on the risk assessment (Figure 19-1, B). As shown in Figure 19-1, A, patients with known cardiovascular, metabolic, or pulmonary disease are classified as having a high risk for sustaining a cardiovascular event during exercise. For these individuals, a comprehensive medical examination and physician-supervised exercise testing is recommended before starting a moderate or vigorous intensity exercise program (see Figure 19-1, B). For individuals who do not have the conditions listed above, the remainder of the algorithm describes how patient signs and symptoms and coronary artery disease risk factors determine the risk classification and exercise testing and supervision requirements. Physical therapists need to screen patients systematically before exercise testing or prescription.

Table 19-1

Cardiovascular Risk Factor Threshold for Risk Stratification

  Risk Factors Defining Criteria
Positive Age Men ≥45 years; Women ≥55 years
  Family history Myocardial infarction, coronary revascularization, or sudden death before 55 years of age in father or other male first-degree relative, or before 65 years of age in mother or other female first-degree relative
  Cigarette smoking Current cigarette smoker or those who quit within the previous 6 months or exposure to environmental tobacco smoke
  Sedentary lifestyle Not participating in at least 30 minutes of moderate intensity (40% to 60% image) physical activity on at least 3 days of the week for at least 3 months
  Obesitya Body mass index: ≥30 kg × m2
– or –
Waist girth:
 >102 cm (40 inches) for men
 >88 cm (35 inches) for women
  Hypertension Systolic blood pressure ≥140 mm Hg and/or diastolic ≥90 mm Hg, confirmed by measurements on at least two separate occasions, or on antihypertensive medication
  Dyslipidemia Low-density lipoprotein (LDL-C) cholesterol ≥130 mg × dL-1 (3.37 mmol × L-1) – or –
High-density lipoprotein (HDL-C) cholesterol <40 mg × dL-1 (1.04 mmol × L-1) – or –
On lipid-lowering medication
If total serum cholesterol is all that is available, use ≥200 mg × dL-1 (5.18 mmol × L-1)
  Prediabetes Impaired fasting glucose (IFG) = fasting plasma glucose ≥100 mg × dL-1 (5.50 mmol × L-1) – or –
Impaired glucose tolerance (IGT) = 2-hour values in oral glucose tolerance test (OGTT) ≥140 mg × dL-1 (7.70 mmol × L-1) but <200 mg × dL-1 (11.00 mmol × L-1) confirmed by measurements on at least two separate occasions
Negative High-serum HDL cholesterol ≥60 mg × dL-1 (1.55 mmol × L-1)

image

Note: It is common to sum risk factors in making clinical judgments. If HDL is high, subtract one risk factor from the sum of positive risk factors, because high HDL decreases CVD risk.

aProfessional opinions vary regarding the most appropriate markers and thresholds for obesity; therefore allied health professionals should use clinical judgment when evaluating the risk factor.

Modified from the American College of Sports Medicine. (2010). Guidelines for exercise testing and prescription, ed 8. Philadelphia: Williams and Wilkins.

image
image
Fig. 19-1 A, Model for risk stratification for cardiovascular disease. B, Guidelines for test selection and level of supervision required based on the risk assessment. (From American College of Sports Medicine, 2010.)

Exercise Testing

Numerous conditions, including nonprimary cardiovascular and pulmonary conditions, have been shown to benefit from the long-term effects of aerobic exercise (Table 19-2) (see Chapters 24 and 25). Thus for each patient with these conditions, the exercise prescription differs. Comparable with prescribing mobilization in acute conditions, prescribing exercise for long-term adaptations is based on the patient’s presentation, history, premorbid status and conditioning level, lab and investigative reports related to physiological reserve capacity, the exercise test, and the goals of the exercise prescription. To promote health, as few as 30 minutes of moderately intense exercise a day on most days of the week is required.3 However, based on ACSM (2010)2 guidelines, optimal aerobic exercise adaptation requires an exercise stimulus of 70% to 85% of HRmax for 20 to 40 minutes, 3 to 5 times a week for at least 6 to 8 weeks. However, the effect of exercise intensity on image and on CO continues to be studied.4 Improvement in image does not appear to be achieved by the same central and peripheral adaptations across a range of exercise intensities. Some individuals have high image, CO, and SV without a history of training.5 This may reflect a genetically determined greater blood volume.

Cardiopulmonary conditions Neurological conditions Endocrine conditions Neoplastic conditions Musculoskeletal conditions Connective tissue conditions Nutritional disorders Conditions requiring organ transplantation Pre- and postsurgical stages Other systemic conditions Other Pregnancy

image

The indications for exercise testing are numerous (Box 19-1). They range from quantifying maximum functional, aerobic, or oxygen transport capacities to assessing endurance during low-level activities of daily living (ADLs). The capacity of the oxygen transport system is the most important determinant of maximum oxygen uptake in healthy people. Metabolic studies including image provide a link between impairment and functional capacity6 and can distinguish cardiac versus pulmonary contribution to exercise intolerance.7 image studies require the use of a nose clip or face mask, which may contribute to perceived exertion in addition to the increased dead space that is created by the inspiratory circuit. In a study comparing the two devices in patients with congestive heart failure, no difference in gas-exchange measurements was observed.8 Perceived exertion, however, was not reported. This is an important finding given that image is a strong predictor of survival (see Chapter 24).

Box 19-1   Common Indications for Exercise Testing in Patient Populations

Contraindications to Exercise Testing

Contraindications to exercise testing and, in particular, maximal testing are classified as relative or absolute (Box 19-2). Absolute contraindications prohibit the safe conduction of an exercise test, whereas the presence of relative contraindications requires that the test, protocol, physiological variables monitored, or end point of the test be modified. Both the indications for the test and any contraindications must be clearly established before performing an exercise test.

Box 19-2   Relative and Absolute Contraindications to Exercise Testing

image

Adapted from Jones NL, Fletcher J: Clinical exercise testing, ed 4, Philadelphia, 1997, WB Saunders.

The guidelines used to test and train healthy people with no disease are not directly generalizable to patients with chronic illness who are medically stable. Because of functional impairments in these patients (secondary to cardiopulmonary, cardiovascular, neuromuscular, or musculoskeletal dysfunction), exercise testing and training must be modified. Moreover, patients who are physically challenged experience more subjective symptoms in response to exercise than do healthy people, so monitoring the subjective responses to exercise is essential. The Borg scale of rating perceived exertion can be modified for clinical use to score breathlessness, discomfort, pain, and fatigue (Table 19-3).9,10 If the end points of the scale have been well described and are understood by the patient, the ratings can be used to compare the patient’s subjective exercise responses over repeated tests. The patient’s subjective reports can be correlated with the exercise response and so can provide a basis for exercise prescription as well as avoiding adverse responses.

Table 19-3

Subjective Scales of Exercise Responses

  Perceived Exertion Breathlessness Discomfort/Pain Fatigue
0 Nothing at all Nothing at all Nothing at all Nothing at all
0.5 Very very weak Very very light Very very light Very very light
1 Very weak Very light Very weak Very light
2 Weak Light Weak Light
3 Moderate Moderate Moderate Moderate
4 Somewhat strong Somewhat hard Somewhat strong Somewhat hard
5 Strong Hard Strong Hard
6        
7 Very strong Very heavy Very strong Very heavy
8        
9        
10 Very very strong Very very hard Very very strong Very very hard
  Maximal Maximal Maximal Maximal

image

Based on the Borg rating of perceived exertion scale.

The functional impairments and capacities of the patient determine the nature of the exercise test; it can be one of various types, depending on the objective of testing and potential training. If exercise training is an objective of the exercise test, the activity used in the test should be comparable to that to be used in training. Physiological responses and adaptation to exercise are specific to the training stimulus (the specificity-of-exercise principle). Thus if walking is to be the training activity, the test should be a walking test, not a cycling test.

Standardization of Exercise Tests and General Procedures

There are numerous variants of standard exercise tests (Table 19-4). They are categorized as continuous tests or interrupted tests. Continuous tests include maximal and submaximal incremental tests and steady-rate tests; interrupted tests include maximal interval and submaximal interval tests. Interrupted tests are designed for patients with low functional work capacity who cannot sustain prolonged periods of aerobic exercise. These patients can perform more work over time when the workload is intermittent. Specifically, the test allows for alternating fixed periods of work and rest or of high and low intensities of exercise. The proportion of work to rest or high to low exercise intensity is set according to the patient’s level of impairment. One patient, for example, may be able to tolerate 3 to 5 minutes of relatively high-intensity work alternated with bouts of 1 to 2 minutes of low-intensity work, whereas another patient may be able to tolerate only 1 minute of low-intensity work alternated with 10 to 20 seconds of rest.

Incremental Incremental work rates, usually 2 to 5 minutes in duration Steady rate Endurance test at a given work rate, usually a comfortable walking or cycling speed Submaximal For patients in whom maximal testing is contraindicated Incremental Steady rate INTERRUPTED TESTS   Maximal or submaximal

image

For maximal standardization and the capacity to perform comprehensive monitoring, stationary exercise modalities such as the treadmill, ergometer, or step are recommended. However, there may be indications to perform an exercise test without a modality, such as the 12-minute walk test or some variant like 6 or 3 minutes.11–13 Standardization of such tests, however, is more challenging. Practice has a significant effect on the results of the 12-minute walk test, so this test must be repeated to achieve a valid test. Also, the instructions for this test are less well standardized clinically than are those for the treadmill or ergometer; this jeopardizes stringent test control and thus must be tightly standardized.14

Like other diagnostic and testing procedures, the validity and reliability of the exercise test depend on standardization of the procedures. Test validity and reliability can easily be compromised in the absence of repeated testing and controls.15,16 Early ergometer training responses at rest along with submaximal heart rates and reduction in EMG activity in the arms and legs can reflect familiarization.17 Repeated exercise tests reflect the marked effects of practice. Practice reduces energy output, improves practice-related coordination, and reduces muscle activation.18 However, with good quality control, a test’s validity and reliability can be maximized, even in patients with severe disease such as chronic heart failure.19 The pre-exercise test conditions and the preparation and testing procedures must be standardized (Box 19-3).

Box 19-3   Pre-exercise Test Conditions

image Establish the indications for an exercise test.

image Determine absolute and relative contraindications to conducting an exercise test.

image Ensure that patient is free of any acute illnesses, including influenza and colds for 48 hours.

image Ensure that patient understands the purpose of the test and provides signed consent.

image Ensure that patient has not eaten heavily, has avoided caffeinated beverages, and has refrained from smoking for at least 3 hours before testing.

image Ensure that patient is rested and has not exercised or been excessively exerted for at least 24 hours before testing.

image Standardize time of day and the influence of circadian rhythm.

image Ensure that patient is appropriately dressed: shorts, nonbinding clothes, short-sleeve shirt, socks, running or walking shoes that have proper support, and secured laces or fastenings.

image Orthoses should be worn unless the test is evaluating changes in functional capacity with and without an orthosis.

image Ensure that patient understands the subjective rating scales and is able to read them when they are held at an appropriate distance.

image Select the type of exercise test, the protocol, and the exercise test termination criteria beforehand.

image Ensure that the patient is familiar with and has practiced performing the test or test activity, preferably before the test day, so as to reduce arousal, improve movement efficiency, and maximize test validity.

image Based on purpose of the test, determine beforehand the premedication status of the patient. If medicated (e.g., bronchodilators or analgesics), ensure that they are at peak effect during test.

image Room temperature (standardized and recorded).

General Procedures for an Exercise Test

image Unnecessary conversation and interaction with the patient are kept to a minimum throughout all stages of the test, including postexercise recovery, so as to optimize the validity of the measurements and the test results overall.

image Resting baseline measures are taken over 5 minutes or until they have reached a plateau.

image Patient stands on treadmill or sits erect on cycle ergometer with feet securely strapped into place on the pedals; the metatarsal heads should be positioned comfortably over the pedals.

image Patient uses two fingers for balance on one side, if possible, when walking on the treadmill, rather than a hand grip; if on the ergometer, does not excessively grasp the handlebar.

image Additional baseline measures are recorded in this position for 2 to 3 minutes or until the baseline is stable.

image The test timer is started.

image The warm-up portion of the protocol begins.

image The selected protocol is carried out.

image Patient is monitored objectively and subjectively at least every couple of minutes throughout all stages of the test, including postexercise recovery.

image The test is terminated when the preset exercise test termination criteria or any of the criteria for prematurely terminating an exercise test are reached.

image The cool-down begins.

image When the cool-down portion of the protocol is complete, the patient moves to the supported chair for the postexercise recovery phase, with legs slightly elevated and uncrossed.

image Postexercise recovery continues until resting baseline measures have been reached or are within 5% to 10%.

image Obtain a report from patient about how patient feels.

image Disconnect the monitoring equipment.

image Continue to observe patient for any untoward postexercise signs or symptoms.

The test is terminated as soon as the sign or symptom criteria for terminating the test are reached or when the criteria for prematurely terminating the test are reached (Table 19-5). Recording the test conditions and procedures in detail is essential. An example of an exercise test data sheet that can be modified to any testing protocol that includes an exercise modality is shown in Figure 19-2, A. Many patients are unable to be exercise-tested using a modality; these patients can walk on a marked circuit, and the results are recorded on an exercise test data sheet similar to the one shown in Figure 19-2, B. Systematic and detailed record keeping will maximize the test’s validity and its interpretation and will ensure that the same procedures are used in follow-up tests, thereby maximizing the comparability of the results of repeated tests. It is imperative that retests be comparable in every respect to the original test in terms of the preparation of the patient and the procedures.

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