1. Chapter 20
Optimizing Abilities and Capacities: Range of Motion, Strength, and Endurance

2. Learning Objectives
State the biomechanical and physiological mechanisms that underlie therapeutic exercise and occupation.
Apply the methods for decreasing edema, minimizing contracture, and mobilization to prevent limitation of range of motion.
Apply biomechanical and physiological principles of the biomechanical approach to the selection of occupations as a means for treating range of motion, strength, and/or endurance problems as needed for occupational performance.
Design treatment goals and therapy for clients who have problems with range of motion, strength, and/or endurance to enhance occupational performance.

3. Musculoskeletal System: Biomechanical Aspects
Kinematic analysis
Describes the amount and direction of movement, speed, and acceleration of body segments and joint angles
Kinetics
Addresses the forces that cause motion or maintain stability
Torque
Tendency of a force to produce rotation about an axis
Lever systems
Effort is the force that causes movement and resistance is the force that tends to keep the object moving.
First-class lever
Second-class lever
Third-class lever

4. Musculoskeletal System: Physiological Aspects
Strength
Muscle hypertrophy
Activity stresses the muscle’s ability to produce tension and force
Result of neural change
Development of more effective neural patterns and neuromotor connections

5. Biomechanical Approach to Treatment: Maintaining or Preventing Limitation in Range of Motion
An individual’s actual ROM at any joint is determined by the structures surrounding the segments that are moving.
Functional ROM is the range necessary to perform daily activities.
Occupational therapists are concerned with providing treatment that helps clients maintain functional motion or to help patients gain motion when there are limitations that interfere with occupation.

6. Factors That Limit Range of Motion
Systemic, neurological, or muscular diseases impair muscle performance.
Joint diseases such as arthritis that create pain and inflammation decrease motion, and surgical or traumatic insults that produce edema and scarring.
Simple inactivity or immobilization affects ROM.
Changes may occur in the muscles, ligaments, joint capsules, tendons, or joints.
This leads to pain, inflammation, and edema.

7. Intervention Methods: Decreasing Edema
Used to prevent ROM limitations secondary to edema
Techniques include the following:
Elevation
Cryotherapy
Compression
Massage
Electrical current

8. Intervention Methods: Minimizing Contractures
Occupational therapists may use therapeutic positioning and splinting.
Therapeutic positioning is designed to help
With edema resolution when limbs are elevated
Preserve function by holding limbs at a proper muscle length
Patients avoid positions that result in tissue shortening or contracture
Splinting used to hold joints in a position with optimum tissue length

9. Intervention Methods: Movement Through Full Range of Motion
Methods for ranging
Teaching the patient to move the joints that are injured, immobilized, or edematous
Passively move the joints if the patient is unable to actively move the joint themselves
Attention must be given to plane of motion, structures involved with the movement of the joint, and joint biomechanics.
AROM or AAROM is preferred to PROM for reduction of edema because the contraction of the muscles helps pump the fluid out of the extremity.
AROM and PROM have no set protocol of frequency.
Occupational therapists often structure activities to promote AROM and PROM to prevent loss of motion.

10. Increasing Range of Motion
If limitations in ROM impair a patient’s ability to function independently in occupations or are likely to lead to deformity, treatment to increase ROM is indicated.
Problems that can be changed
Contractures of soft tissue
Skin
Muscles
Tendons
Ligaments
Problems that cannot be changed
Ankylosis or arthrodesis
Long-standing contractures
Severe joint destruction

11. Increasing Range of Motion: Stretching
Stretch is a process by which the target tissue is lengthened by an external force, usually through manual therapy or through the use of splinting, casting, or external equipment.
Change is only created when tissue is stretched repeatedly or sustained over time.
Factors that determine the effectiveness of stretching are the duration, the intensity, the speed, and the frequency of the stretch being applied.
Gentle, controlled stretching that achieves small increments of gain over time is thought to be more effective than vigorous stretching aimed at large, rapid gains.

12. Intervention Methods for ROM: Active Stretching
The use of occupation for stretching is empirically based on the idea that a person involved in an interesting and purposeful activity will gain greater range.
Because occupations can be performed using a number of muscle patterns, the therapist must determine how the patient completed the activity prior to injury.

13. Intervention Methods for ROM: Active Stretching—(cont.)
Occupations used as a means to increase ROM must provide a gentle active stretch by use of slow, repetitive isotonic contractions of the muscle opposite the contracture or by use of a prolonged passive stretched position of the contracted tissue.
Exercises that increase the range of shortened tissue are the proprioceptive neuromuscular facilitation (PNF) techniques called contract relax and agonist contraction.

14. Intervention Methods for ROM: Passive Stretching
Preparatory method for increasing ROM so patients are able to engage in purposeful activity
Techniques
Manual stretch
Use of orthotic devices
Splints
Casts
Home program on specific joint stretches
Pilates, yoga, or the ROM dance
These tasks can be integrated into a patient’s daily occupations.

15. Biomechanical Approach to Treatment: Strengthening
If limitations in a patient’s strength prevent participation in occupations or may lead to a deformity, treatment aimed at increasing strength is warranted.
If weakness prohibits patients from moving the limb or maintaining a functional position, their lack of regular active range of motion may lead to contracture.
Occupation or exercise parameters that may be manipulated to increase strength include the following:
Type of contraction and speed
Muscles involved
Intensity of task

16. Intervention Methods for Strengthening: Occupations and Exercise
Therapists may find that various occupations provide sufficient opportunities for muscle strengthening and are more effective at maintaining the patient’s interest and motivation than exercise alone.
Exercise may be used as a warm-up to occupation, or occupation may be introduced to enhance carryover of the strength gained by exercise.

17. Grading Muscle Strength Parameters
When prescribing a strengthening program, therapists can manipulate the exercise or occupational parameters.
Amount of resistance imposed on the contracting muscle or muscle groups during each repetition is increased.
40%–60% of one-repetition maximum (1 RM)
Training volume: Changing the number of repetitions of an activity, changing the number of sets required of that one activity, or changing the number of activities done during a treatment session.
Rest period between activity should be 3–4 minutes for high loads or repetitions; rest period of 1–2 minutes for low intensity or low repetition activity.
Patients starting a strengthening program should exercise 2–3 days a week, which can then increase to 3–5 days a week as the strength progresses.

18. Biomechanical Approach to Treatment: Increasing Endurance
Factors that influence muscle endurance
With activities that call for maximum muscle contraction, such as lifting heavy loads, more motor units must contract simultaneously without the opportunity to recover, resulting in quicker fatigue.

19. Intervention Methods: Increasing Endurance
Provide patients with interest- sustaining occupations that can be graded along the dimension of time or repetition.
Work with patients to schedule their everyday routines so that they gradually increase the amount of time they engage in occupations throughout the day and/or gradually increase the duration of engagement in one particular occupation.