Therapeutic Exercise

Anatomy and Physiology

The specific anatomy of each joint involved will not be covered here. Therapeutic exercise can theoretically involve all joints. This article will present the basics of exercise physiology here.

The main benefits of exercise involve long term adaptation include effects upon the musculoskeletal, metabolic, cardiovascular, and respiratory systems. In the injured or ill individual, the benefits of exercise include recovery and restoration of function, including the range of motion, increased cardiopulmonary reserve, and functional status along with numerous benefits for diseases such as diabetes (in terms of insulin resistance). The main measurement of exercise capacity is the lactate threshold and maximal oxygen uptake (know as VO2 max).[1][2]

The maximal oxygen uptake (VO max, L/minute) reflects the ability of a person to imbibe, transport, and use oxygen, which defines that person's functional aerobic capacity. This capacity, as is the gold standard of cardiorespiratory fitness.[2]

•  VO max (ml/kg/min) = 79.9 – (0.39 x age) – (13.7 x sex (0=male, 1=female) – (0.127 x height)[2]

Skeletal muscle metabolism — Muscle contraction and relaxation depend primarily upon hydrolysis of ATP, which releases the chemical energy necessary for binding of the protein myosin with actin filaments to allow myosin to slide along the actin filament leading to mechanical contraction.[2]

Exercise has been validated as a treatment for osteoarthritis with benefits extending at least 2 to 6 months after cessation of the formal training regimen. Exercise appears to have anti-inflammatory effects as well as nourishing the joints themselves through pushing more synovial fluid through the joint.[3]

Indications

Indications for therapeutic exercise are for mostly uncomplicated musculoskeletal disorders, cardiopulmonary disorders but depends on a variety of factors. Generally, exercise is indicated for all non-acutely ill adults and children up to their level of ability. It is a well-established fact that exercise has many benefits and can specifically target certain musculoskeletal conditions, including osteoarthritis, patellofemoral disorder, risk of falls, and can help with recovery from illness.[4]

Contraindications

Contraindications to exercise include acute illness or injury. The recommendation is to recover to full functional capacity before beginning any exercise regimen. Exacerbations of chronic disease can be detrimental to exercise capacity, and general recommendations include having chronic conditions under control beginning starting exercise. There are alternatives in these populations. For example, patients with acute arthritis flares are often able to perform water and pool-based exercises that are low-impact on joints. Cardiac conditions that qualify for exclusion are valvular heart disease, ventricular hypertrophy, dangerous arrhythmias, and malignant hypertension. In most cases, the great benefits imparted by exercise outweigh the small risks involved with increased activity.[5][4]

Equipment

Equipment greatly depends on the type of exercise involved. These are as follows.

1. Aerobic exercise: often requires no equipment in terms of running outside but a patient may choose to use such machines as ellipticals,
2. Strength exercise: usually involves the use of weights. In calisthenics, one often requires gymnastic equipment.
3. Mobility: usually involves static and dynamic stretching. Time stretching does not count towards the recommended 150 minutes of exercise per week. Most patients who exercise using every major joint do not need to incorporate specific mobility work.[4]

Personnel

Personnel depends on the type and level of therapeutic exercise. For cardiac and pulmonary rehabilitation, there is an interprofessional requirement for Physical therapists, occupational therapists, and all levels of clinical involvement due to the acuity of patients involved. For individual sports injuries, only physical therapists may be necessary to guide the patient through specific regimens. Incorporating home exercises that are easy and safe to perform alone allows peripheral surveillance with minimal risk.[4]

Preparation

A clinician should fully evaluate all persons beginning an exercise prescription or regimen with a focus on specific risk factors that they may have. An in-depth assessment should take place as to the acuity of condition, the type of disease, comorbid factors.[6]

Technique or Treatment

Therapeutic exercise mainly falls into three categories

1. Endurance training: Defined as the use of large muscle groups in the area of 50 to 60% VO2Max to achieve greater cardiovascular endurance.

1. Resistance training: This modality increases overall strength and comes in three forms: isotonic, isometric, and isokinetic. Isotonic consists of dynamic movements with a constant load. Isokinetic involves a constant velocity with variable load. Isometric involves muscle contraction that is static with no change in muscle length. All forms of resistance training have favorable effects on diabetes, osteoporosis, and cancer with increases in bone mineral density, increased bowel transit time, increased glucose uptake in muscle, and improvements in back pain.
2. Flexibility training: slowed, controlled exercises performed in a gradual manner (usually in the increment of fifteen to thirty seconds) that aid in the range of motion at joints or series of joints. Three main types exist: static, dynamic, and PNF (proprioceptive neuromuscular facilitation).

Static involves held positions that are effective with little required in terms of assistance and time.

Dynamic involves repetitive bouncing movements that produce muscle stretch over time.

PNF involves alternating contraction and relaxation of agonist/antagonist muscles at specific joints that generally produce the largest increase in flexibility.

All of these are combinable into exercise programs that work for many different types of patients. Different subtypes of modalities can help to increase effectiveness or allow participation of individuals with special needs based on comorbidities. One such example would be aquatic therapy for stroke patients with balance difficulties.[7]

Basic exercise prescriptions should follow the FITT mnemonic.

• F- frequency: number of days per week
• I- Intensity: low, moderate or vigorous
• T- Time: minutes per session for endurance exercise
• T- Type: endurance, strength, flexibility or some combination

Exercise programs require individualization according to the age of the patient, severity of OA, and/or comorbid disease. The analytic exercises for improvement of muscle strength in hip OA aim to influence the hip abductors, adductors, flexors, and extensors. In knee osteoarthritis and pathology, the target muscle groups are thigh muscles such as the quadriceps muscle and posterior group of thigh muscles), calf muscles (triceps surae muscle), as well as muscles, are the hip joint such as gluteus and sartorius. Beyond this, there are no documented or established specific programs for therapeutic exercises regarding the intensity, frequency, and interval of joint load.[8]

For selected populations:

Diabetes mellitus

Exercise is essential in diabetes prevention and management. Exercise has positive effects on glucose metabolism and decreasing insulin resistance, a hallmark for diabetes mellitus type 2. Exercise improves insulin sensitivity by acting on muscle physiology. Increasing glucose transporter 4 (GLUT-4) content and increasing glucose transport. Exercise decreases free fatty acid in the bloodstream by reducing levels of obesity. It also increases insulin-stimulated limb blood flow. Increased resistance training increases muscle mass, which in turn affects glucose uptake.

Exercise slows peripheral neuropathy development by an unknown mechanism. One theory is that exercise promotes endoneurial blood flow and greater oxygen delivery to nerves.

Osteoarthritis

Therapeutic exercise has great potential to reduce pain and improve muscular strength, balance, and range of motion in individuals with osteoarthritis. Resistance training and endurance training are especially beneficial for pain and balance with osteoarthritis in large joints such as the knee. The most validated is isokinetic exercise for the knee.

Complications

The complications of therapeutic exercise are mainly related to poor technique that contributes to acute injury or decline in function. When performed correctly, it is extremely rare to experience any ill side-effects from therapeutic exercise.[9][10][8]

Clinical Significance

A normal exercise capacity for age usually excludes respiratory and cardiac problems for most diseases. For specific muscular and skeletal injuries, therapeutic exercises targeted at strengthening and rehabilitation represent a pathway to normal functioning. For pulmonary and cardiac disorders, therapeutic exercise offers a path to restoration and maintenance of function essential to the quality of life.

Physical activity is recommended by the US dept of health and human services for maintenance of function and continued health and came out in November 2018. Persons aged 3 to 5 years: physically active throughout the day. Persons 6 to 17 years: 60 minutes or more of moderate to vigorous activity per day. Persons 18 to 65: 150 to 300 minutes of moderate aerobic physical activity or 75 to 150 min/week of vigorous activity or equivalent combination of these. Persons 65 and older: multiple modalities of balance training, aerobic activity, and muscle-strengthening activity.[11][12][13]

Enhancing Healthcare Team Outcomes

The effectiveness of therapeutic exercise, exercise prescriptions, and physical therapy on musculoskeletal disorders, as well as cardiopulmonary disorders, diabetes, hypertension, and other chronic health problems, are well-established. Many clinical trials have been done on the effectiveness of these as well as clinical experience guides the resolution of many MSK type problems with a simple treatment of underlying movement patterns and strengthening without surgical intervention. Researchers have conducted several large-scale studies on specific disorders such as "Timing of Physical Therapy Initiation for Nonsurgical Management of Musculoskeletal Disorders and Effects on Patient Outcomes: A Systematic Review," which is an extensive analysis of 3855 articles initially screened with 14 studies included.[14][15][16][17]