Effects of Ageing on Hand Function

Original Editor - Lucinda hampton Top Contributors - Lucinda hampton, Mohit Chand, Uchechukwu Chukwuemeka, Kim Jackson and Shaimaa Eldib

Original Editor - Your name will be added here if you created the original content for this page.

Top Contributors - Lucinda hampton, Mohit Chand, Uchechukwu Chukwuemeka, Kim Jackson and Shaimaa Eldib  

Introduction

Hand function decreases with age in both men and women, especially after the age of 65 years. Deterioration in hand function in the elderly population is, to a large degree, secondary to age-related degenerative changes in the musculoskeletal, vascular, and nervous systems. Deterioration of hand function in elderly adults is a combination of local structural changes (joints, muscle, tendon, bone, nerve and receptors, blood supply, skin, and fingernails) and more distant changes in neural control. These age-related changes are often accompanied by underlying pathological conditions (osteoporosis, osteoarthritis, rheumatic arthritis, and Parkinson's disease) that are common in the elderly population.

Age and grip strength are significant predictors of hand dexterity Aiming and tapping hand dexterity (involving rapid, coordinated, goal-directed actions) is moderated by the factor of grip strength more than age ie physical activity may improve particular types of hand dexterity. 

• Musculoskeletal hand problems are common in the population aged over 50 yrs.
• Hand function seems to remain stable until age 65 years, after which it gradually reduces.
• After age 75 years, age differences in performance is apparent.
• Most are painful and have a significant impact on everyday life.
• Women and the very old appear especially vulnerable to the effect of hand problems on their daily activities.

Factors Affecting Function in Aging Hands

Extrinsic Factors

• Environmental factors (ultraviolet radiation, chemical irritants)
• Physical activities (work-related, recreational sports, and hobbies)
• Nutrition
• Traumatic injuries

Intrinsic Factors

• Genetic factors
• Endocrine factors
• Metabolic disorders
• Diseases (osteoarthritis, rheumatoid arthritis, osteoporosis)

Pathological changes

• soft tissues (muscles, tendons, blood vessels, nerves)
• hard tissues (bone, hyaline cartilage, fingernails)

Muscles

One of the most common changes in aging skeletal muscle in the body is the major reduction in muscle mass ranging from 25% to 45%, ie “sarcopenia of old age”. The diminished muscle strength of the aging hand is attributed to decreasing muscle mass.The are 11 intrinsic muscles and 15 extrinsic muscles with direct functional roles in the hand.

• There is a significant reduction in both action potentials and in the number of viable motor units associated with the hand muscles in the elderly.
• Extrinsic and intrinsic hand muscles produce the force required for gripping objects (grip force).
• After 60 years of age, there is a rapid decline in hand-grip strength, by as much as 20–25%, accompanied by a substantial loss of muscle fibers and decreased muscle-fiber length, particularly in the Thenar muscle group.
• The thumb intrinsic musculature constitutes approximately 40% of the total intrinsic musculature of the hand.
• Three of the main thumb muscles play important roles in stabilizing the thumb during strong pinch grips of objects and these commonly show age-related dysfunction.
• The contractile capacity of the Thenar muscle in elderly people has been assessed finding higher muscle fatigue resistance in elderly adults, attributed to differences in both the PNS and CNS.

Tendons

Tendons are composed of dense connective tissue, primarily formed by densely packed, orderly arranged, collagen fibers.

• Tendons have a very poor blood supply and are virtually avascular in the regions of tendon insertion.
• The primary function of tendons is to attach muscles to bone and to transmit muscle force to the skeletal system with limited stretch or elongation.
• Changes due to aging cause reduced microcirculation of the synovial sheaths of the tendons and tendons unit, causing difficulties in the ability to adapt to environmental stress, decreased range of joint motion, and decreased flexion. This may also cause flexion contractures of the overlying joints.
• The tensile strength of tendons is a measure of elongation of the tendon during tensile testing, the ultimate tensile strength values for aged tendons decrease by 30–50%.
• Biochemical changes in the aging tendons result in a stiffer, more irregular dense connective tissue. This involves a reduction in water content accompanied by a loss of proteoglycans and also degradation of the collagen type I fiber.

Intrinsic Bones and Joints

With aging, the hand bones (19 long bones and 8 short bones) and joints, especially the synovial joints, are accompanied by morphological and pathological changes common to aging skeletal tissues.

• Aging hands and fingers are especially prone to osteoarthritis and rheumatoid arthritis. Osteoarthritis of the hand and finger joints is a disease process that destroys interphalangeal cartilage, synovial membranes, and the joint capsule. Consequences of osteoarthritis of the fingers include pain, swelling, joint deformities, bone spur formation, restricted range of motion of wrist and fingers, and difficulty in performing manual activities that require grip and pinch.
• After the age of 50, the bone density of the hand decreases by approximately 0.72% per year.

Fingernails

Functionally, nails are important tools for fine grip and manipulation of small objects in various ways.

The rate of fingernail growth diminishes with aging.

Age-associated nail changes are common in elderly people. These may involve

• Discoloration with changes in color from white-pink to yellowish-gray
• Changes in contour (longitudinal ridges, or less concave shape)
• Changes in the thickness and roughness of the nail surface.
• Structural changes include brittle nails; onychauxis (hypertrophic nail); subungual exostosis (a variant of osteochondroma).
• The most common disorders of aging fingernails are common fungal infections.
• With the loss of manual dexterity with aging, elderly adults may not be able to cut their own nails and commonly require manicure assistance.
• Several of the changes in aging fingernails may be symptoms of underlying disease or metabolic disorders and can provide diagnostic indications for the physician. The translucent nature of the nail plate enables the coloration of the underlying nail bed, predominantly provided by the dermal vascularization, to be seen; this can provide an indication of problems such as anemia.

Nerve Changes and Hand Motor Control

Loss of functioning of motor neuron and ventral root axons has been demonstrated in the elderly population, approximately 25% of the motor axons in hand muscles are lost in old age.

• There is a reduction in the number of myelinated nerve fibers from the seventh and eighth cervical nerve roots, together with diminished nerve fiber diameters.
• Muscle twitches become smaller and slower.
• There are loss of motor units after the age of 60, although they are less obvious in the Hypothenar group. The motor units in the Thenar and Dorsal interossei muscles decrease significantly with age.
• Muscles in elderly adults have fewer (but on average larger and slower) motor units, which has an important effect on both motor control and function. There is a critical decline in age-related motor performance, which has been attributed to loss of motor neurons .
• There is evidence indicating that age-related changes occur in both neurohistology and in responses to neurotransmitters.
• The integrity of the CNS is reflected in the cognitive and psychomotor ability of the individual. For a successful prehension task, CNS control processes of negative and positive feedback mechanisms are needed. This motor task requires the integrity of a circuit of interconnected hand-related areas, including a ventral subdivision of the premotor and sensorimotor cortical areas, the cerebellum, and the basal ganglia. With physiologic changes this may be affected, affecting prehension tasks.

Sensory Changes in the Aging Hand

Our senses and sensory integrity decline with aging. An understanding of the somatosensory system of the hand is important for therapists.

• Accurate functional sensory input is essential for well-controlled precision manipulation of small objects needed for many different activities of daily living. This requires refined coordination of forces exerted on the object by the tips of the finger and thumb.
• Peripheral decrement in tactile sensibility contributes to slowness in processing afferent information associated with hand movement.
• The effects of old age on fingertip force responses have indicated degraded central information processing and deterioration of cutaneous mechanoreceptors.

Skin Changes in the Aging Hand

• Elderly people are more susceptible to feeling cold in their hands than younger people, and this is probably due to the poorer blood flow in the elderly hands.
• Reduced sensitivity to local heat sources or slower reflexes may explain the increased incidence of burns to the hands of the elderly population (hot water scalding).
• The thin skin of the dorsal aspect of the hand undergoes morphological changes with aging and becomes much thinner.
• The numbers and activities of sweat and sebaceous glands are also reduced in elderly people, who find it more difficult to accommodate to environmental heat stress. One of the consequences of the thinner dorsal hand skin in elderly adults is that it is more fragile, drier, and heals more slowly after injury.
• Obvious signs of dorsal skin aging of the hand are wrinkling and loss of elasticity, resulting from changes in the amount and biomechanical properties of the elastic fibers in the
• The reduction in tactile sensation of fingers in elderly adults is due to the loss of the various sensory mechanoreceptors (Pacinian corpuscles, Meissner corpuscles, etc.).

Functional Movements of the Hand and Fingers

• Tests show that in elderly people the largest declines in upper extremity functioning (greater than 50%) are in hand-force steadiness, speed of hand-arm movements, and vibration sense. 
• Hand function remains fairly stable until the age of 65 years, after which it diminishes slowly. After the age of 75 years, age differences in performance become more apparent as seen in prehensile pattern frequency, hand strength, performance time, and range of motion. The percentage decrease in strength with age is similar for men and women regardless of their lifestyle.
• By the age of 90, an individual may be expected to have wrist range-of-motion (ROM) values that are approximately 60% of those of average 30-year-old individuals, affecting functional hand activities.
• Difficulties to adduct the thumb cause elderly people to substitute thumb adduction by using thumb flexors to compensate for their weakness (Froment's sign is positive).
• Aging has marked degenerative effects on hand function, age-related declines in hand and finger strength and the ability to control submaximal pinch posture, manual speed, and hand sensation occur. Moreover, a gender difference was also found, with elderly women experiencing more serious declines in fine manual dexterity and strength than men of a similar age.

Therapeutic Exercises and Ergonomic Devices for the Aging Hand

Functional aging changes in hands can possibly be retarded by introducing suitable simple regular hand exercise programs for hand strengthening and hand flexibility. It is important that the exercises selected are appropriate and do not lead to damage or overexertion

• Exercise can be very simple eg squeezable rubber balls, or elastic bands on fingers and exercises to strengthen grip and maintain joint flexibility of fingers and the wrist. See home-exercise plan below.

Ergonomic devices are important: modifying tools and instruments of daily living for the elderly population, especially those with impaired functioning. eg basic items such as cutlery, pens, scissors, nail clippers, hairbrushes, and combs. Large phone pads.

Simple Home Exercise Plan

1.     Finger Bends

A simple home exercise plan that keeps the joints in fingers moving. For best results, perform these bends on each individual finger of both hands.

• Begin by holding up your right hand straight.
• Bend your thumb downward in the direction of your palm.
• Hold the bend for two to five seconds.
• Straighten your thumb.
• Repeat on each finger on the right hand.
• Repeat the entire sequence on the opposite hand.

2.     Make a Fist

How to Make a Fist

• Start by holding your right hand up and straight (as if you were going to shake someone’s hand). Keep your wrist and forearm close to a tabletop or another flat surface.
• Close your fingers together to create a gentle fist. Try not to squeeze your fingers into your palms.
• Slowly and gently return your fingers to the starting position.
• Repeat multiple times on each hand.

3.     Thumb Bends

How to Perform a Thumb Bend

• Start by holding your right hand up and straight – just as you did with the previous exercise.
• Bend your thumb down and inward toward your palm.
• The goal is to reach for the bottom of your pinky finger, but don’t worry if you cannot reach that far just yet.
• Hold the bend for a few seconds.
• Return to the starting position.
• Repeat 10 times.
• Repeat on the left hand.

4.     Make a “C”

How to Make a “C” With Your Hands

• Begin with your right hand up and your fingers straight.
• Curve your fingers downward and your thumb out and to the side to create a “C” shape.
• Return to the starting position.
• Repeat multiple times on your right hand.
• Repeat on the left hand.

5.     Finger Lifts

How to Perform Finger Lifts

• Start with your hand palm-side down on the table.
• Lift your thumb slowly off the table.
• Hold for two seconds.
• Gently lower your thumb back down.
• Repeat on each finger.
• Repeat the entire sequence on the opposite hand.

6.     Wrist Stretches

How to Perform Wrist Stretches

• Begin with your right arm stretched out in front of you, hands flat.
• Gently press down on your right hand. The tips of your fingers should be facing the floor.
• Hold the stretch for a few seconds.
• Repeat 10 times.
• Repeat on the left hand.

7.     Give the Okay

• Begin with your hand up and straight (as if you were going to shake someone’s hand).
• Create an “O” shape by touching your thumb to your index fingertip.
• Next, touch your thumb to your middle fingertip.
• Repeat the same movement on the remaining fingers.
• Repeat the sequence multiple times.
• Repeat the entire exercise on the opposite hand.