W–Z

weight and pain The influence of excessive body
weight on the experience of PAIN. Excessive body
weight may itself be the cause of pain, particularly
pain that affects the joints, or may contribute to
pain due to underlying health conditions such as
FIBROMYALGIA, ANKYLOSING SPONDYLITIS, PLANTAR
FASCIITIS, and GOUT. OBESITY is a risk factor for
numerous chronic conditions that cause pain
including OSTEOARTHRITISand chronic BACK PAIN.

Excessive Body Weight

and Musculoskeletal Structures

Excessive body weight has numerous adverse
effects on the musculoskeletal system because it
alters the person’s posture and movement. The
effects are most noticeable on the joints, which
may develop chronic discomfort and aching. Every
10 pounds of body weight in excess of healthy
weight increases the force the knees experience
during walking by about 50 pounds each time the
foot strikes the ground. Weight-bearing joints
below the waist (hips, knees, ankles, and feet) are
particularly vulnerable to weight-related pain.
Because excessive body weight strains muscu-
loskeletal structures, it often contributes to pain
symptoms related to chronic conditions such as
back pain. The pressure of the excessive weight
over time may also cause damage to the joints;
numerous studies implicate overweight and obe-
sity in the development or escalated progression of
osteoarthritis, the most common degenerative dis-
order affecting the joints.

Physical Activity and Pain Relief

Regular, moderate physical activity often improves
chronic pain regardless of its source. Exercise, par-
ticularly activities that extend 20 minutes or
longer, causes the body to release endorphins and

other substances that act like natural pain reliev-

ers in the brain. The effects of these substances

lasts far longer than the exercise session.

Regular physical exercise also strengthens mus-

cles and connective tissues and broadens flexibil-

ity. These effects increase the stability of the joints,

improving joint function. Even when pain is unre-

lated to the joints, these effects are beneficial for

most underlying health conditions for which pain

is a key symptom. And regular physical activity

improves cardiovascular function, notably circula-

tion, increasing the flow of blood to all parts of the

body. Increased blood flow brings oxygen and

other vital substances to areas of HEALING, helping

both to speed healing and to keep scar tissue from

stiffening.

However, the natural tendency is to avoid

activity when pain is present. A reduced level of

activity may be appropriate for certain health con-

ditions, especially for a defined period of recovery

time. Extended inactivity contributes to, rather

than relieves, pain. It may also give rise to other

health complications such as DEEP VEIN THROMBOSIS

(DVT) or PULMONARY EMBOLISM(blood clots in the

veins of the legs or in the lungs), pneumonia

(fluid accumulation in the lungs, and pressure

sores or decubitus ulcers. Extended inactivity also

tends to encourage further weight gain, even

when food intake remains the same, because

reduced movement means the body uses less

energy.

Appropriate Physical Activity

The doctor can recommend activities and intensity

levels that are appropriate for both the health con-

dition and the person’s FITNESS LEVEL. A physical

therapist or qualified fitness and training expert

can develop a customized program for progressive

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