Head and neck

Assessment of the head and neck area is reviewed in Chapter 9.

Upper extremities and torso

The clavicle lies in a horizontal plane above the first rib and rotates between the sternum and the superior surface of the scapula (Figure 18-2). The scapula, a large, flat triangular bone, forms the posterior portion of the upper extremity and the superior, lateral angle articulates with the capsule or rounded head of the humerus, the large bone in the upper arm. The distal end of the humerus forms the condyle and is divided into the medial epicondyle and the lateral epicondyle. The proximal end of the ulna attaches at the articulating surface of the humerus and forms one of two long bones in the forearm. The olecranon is the outer, rounded distal surface of the ulna and forms the major portion of the elbow. The distal end of the ulna is small and articulates with the wrist bones. The radius is along the lateral side or thumb side of the forearm, and the distal end of the radius forms a large portion of the wrist bones.

The hand consists of eight carpal and five metacarpal bones. Many of the carpal bones are cartilaginous at birth. A radiograph of a child’s hand at 2½ years of age illustrates ossification of only the capitate and hamate bones in the hand. Development and ossification of the hand continues until 11 years of age when all of the carpal bones are ossified except for the small pisiform bone, which develops by 12 years of age. Abnormalities of the phalanges, or fingers, such as syndactyly, webbing, or fusion between adjacent digits of the hands or feet, may be indicative of profound developmental delay (Figure 18-3). Polydactyly, the presence of supernumerary digits, is a more common variant and is not usually associated with other congenital anomalies.

Spine

The infant has a C-shaped spinal curve at birth in comparison to the double S curvature that is present in late adolescence. Thoracic and pelvic curves are present at birth, and the secondary cervical curve is present by 3 to 4 months of age when the infant begins to hold up his or her head. The lumbar curvature begins to form as the infant bears weight and begins to walk. The young child often has an exaggerated thoracic-lumbar curvature and a protuberant abdomen until 3 years of age, when gait and balance become more normal (Figure 18-4). The sacrum is composed of five separate bones at birth and by 18 to 20 years of age is fused into one large bone. The coccyx consists of three or four small bones that begin to ossify between the first and fourth years of life and fuses into one bone by 25 years of age (Figure 18-5).

Pelvis

The hip bone contains three distinct parts in childhood, which are later fused in adulthood. The ilium is the superior, broad, flat surface of the hip bone. The ischium is the strongest portion of the hip bone; it contains a portion of the acetabulum, which forms the attachment at the hip bone for the femur and the opening or foramen. The pubis contains the medial portion of the acetabulum and joins medially to form the complete pelvic girdle.

Lower extremities and feet

The femur is the longest and strongest bone in the body. The head of the femur becomes ossified during the first year of life, but the shaft of the femur does not become completely ossified until 14 years of age. The long bones of the extremities continue to grow at the site of the epiphyseal plate throughout childhood and adolescence; peak bone mass is achieved by young adulthood. In the lower leg, the larger bone is the tibia, the proximal end articulates with the femur and the distal end forms the medial malleolus of the ankle. The fibula is the smaller bone in the lower leg and lateral to the tibia. The distal end of the fibula forms the lateral malleolus of the ankle.

The patella is the small triangular bone that forms the kneecap and lies over the junction of the femur and the tibia. The health of the patella during growth and development depends not only on strong bone growth but also on the strength of the ligaments and tendons supporting the patella.

The seven tarsal bones and five metatarsal bones of the foot undergo dramatic ossification during the first year of life. The ossification of the bones in the foot follows the normal development of the gross motor milestones. The talus is ossified by the seventh month of life to form the ankle, and the remaining metatarsal bones continue to form during the latter half of the first year of life. The phalanges continue the ossification process through adolescence.

The limbs go through a continuous process of rotational change until about 8 years of age. The torsional development is a process that begins in infancy and progresses from sitting position to pulling up, to crawling, then standing, cruising, and finally walking with an exaggerated gait and a wide base of support. The laxity in the ligaments and the torsional forces in the intrauterine environment as well as sitting and sleeping patterns in the early years are responsible for the normal variations in the lower extremities during childhood. Torsional variations and abnormalities are hereditarily linked and often show a strong family tendency.

Monitoring growth

During growth, bone has the remarkable capacity to remodel itself. Bone is deposited in areas subjected to stress and reabsorbed in areas where there is little stress. This physiological process explains the ability of children to remodel residual deformity after fractures and explains the biological plasticity in growing bones. The rate of bone growth is greatest in the lower extremities before the onset of puberty; the distal extremities reach adult size in early puberty, which is reflected in shoe size in preadolescents. The trunk and proximal extremities exhibit the dominant growth during puberty and into young adulthood. Bone growth is completed at age 20 years, and peak bone mass is achieved by age 35 years.

Monitoring the velocity of growth is the key focus of routine well-child visits and when following children with chronic health conditions. For the child with slow growth or delayed onset of puberty, obtaining past growth charts and evaluating the progression of the growth curve along with familial patterns of growth and pubertal development is critical to assessing an abnormal growth pattern.

Muscle development

The rate of muscle growth and development increases rapidly beginning at age 2 years. Early muscle growth is balanced by a normal decrease in adipose tissue in early childhood.¹ The growth and maturation of the muscles continues with the ossification of the skeletal system (Figure 18-6). Muscle tone is the state of normal tension of the muscles, and term infants normally have strong muscle tone at birth. Abnormalities in muscle tone in an infant may be noted shortly after birth when an infant is floppy. Less than normal muscle tone is described as hypotonia; rigidity or increased muscle tone is known as hypertonia; and spasticity is resistance to flexion and extension and range of motion of the muscles. Normal muscle function requires the normal function of the lower motor neurons (LMNs) in the spinal cord and the normal reflexivity of the muscle fibers. Normal muscle tone requires the normal function of the spinal cord stretch reflex and the balance of the upper motor neurons (UMNs) and LMN function. Lesions on the UMNs result in increased tone and LMN lesions result in decreased tone.

The greatest increase in muscle size occurs during puberty when boys’ muscle mass and muscle cell size begins to exceed that in girls. In early and middle childhood, girls’ muscle size increases at a greater rate than in boys up until puberty.

Preparation for the examination

For a thorough and complete assessment of the musculoskeletal system, infants must be undressed except for the diaper, and children must be undressed except for underwear. A young child cannot be thoroughly assessed when wearing socks and shoes or when gowned. In preadolescence and adolescence, maintaining modesty while assessing the spine can be challenging, particularly in girls. Maturing females must be in underwear and gown to obtain a thorough examination of the spine. Musculoskeletal terminology is presented in Box 18-1, and skeletal positions are presented in Figure 18-7.

Inspection and palpation

Initial inspection of the musculoskeletal system in the child from birth to adolescence begins with inspection of skin for color and temperature; inspection of palmar creases; and noting of scars, unusual pigmentation or lesions, swelling, and bruising. Bruising is the most common sign of physical abuse and intentional injury in children. Bruising over bony prominences such as the shins, knees, and forehead are common in children and usually the result of active play. However, bruising seen on the buttocks, neck, face, and earlobes should be considered suspect and require further information gathering and assessment for signs of abuse.² Erythema, swelling, tenderness, or temperature changes should also be noted over the joints or extremities.

Observation of posture when standing and sitting, assessing the proportion of upper extremities to lower extremities, and noting any obvious gait abnormalities are part of a complete musculoskeletal assessment. Palpation for bone or joint tenderness, and any unusual prominence, thickening, and/or indentations in the bony skeleton as well as muscle tone, muscle strength, and symmetry should be evaluated. Inspection, palpation, and assessment of the mobility of the spine and range of motion of the extremities, including the evaluation of the mobility of the joints, are included in a thorough and complete assessment of the musculoskeletal system.

Joints

Joints in the body have a slightly moveable to freely moveable motion throughout the period of growth and development. The hinge joint, between the humerus and the ulna, permits motion in one plane, whereas the pivotal joint, between the radial-ulnar joint, allows rotation only. The condyloid joint in the wrist allows flexion, extension, adduction, abduction, and circumduction. Saddle joints, such as in the thumb, have a similar motion to the condyloid joint in the wrist except that the joint forms a concave-convex fit to achieve motion. The hip and shoulder joints are examples of ball-and-socket joints. Finally, the gliding joints allow a gliding motion between two flat surfaces, such as in the vertebrae and carpal joints in the hands and feet (Figure 18-8).

Head and neck

Assessment of the head and neck is presented in Chapter 9.

Upper extremities and clavicle

In the newborn infant, the clavicles should be fully palpated to detect a possible fracture often associated with a traumatic delivery. Localized tenderness at the proximal end of the clavicle shortly after birth often leads to a palpable bony prominence as the fracture heals. A full range of motion of the upper extremities, including the elbows and wrists must be evaluated to determine any trauma that may have affected the clavicles or shoulders during the birth process. In Erb palsy, injury to the fifth and sixth cranial nerves, no spontaneous abduction of the shoulder muscles or flexion of the elbow is noted on examination. The arm is adducted and internally rotated, but normal grip in the hand is present.

Range of motion should be passively evaluated in infants and young children and assessed actively when children are cooperative with examination. Any limitation of range of motion in joints and extremities or asymmetrical response should be further investigated. Muscle tone and strength should also be evaluated. In early childhood, the radial-ulnar joint is particularly vulnerable. Subluxation, or partial dislocation, of the radius from the humerus, often referred to as Nursemaid’s elbow, is common in children from 2 to 4 years of age. Often there is no clear history of trauma, but laxity of the ligaments in the young child predisposes them to injury. In cases of a subluxation, the child usually refuses to use the affected arm. Passive range of motion is possible except for supination (palm facing upward). Dislocation of the shoulder can also occur in the young child and is marked by swelling, pain, and a limp arm.

Trauma to the upper extremities is common in children and adolescents. Strains, sprains, or fractures can occur with strenuous activity, falls, motor vehicle or pedestrian injuries, or participation in competitive sports. Careful assessment is warranted in the growing child when any history of trauma is obtained. Fractures that are highly suggestive of intentional injury or abuse in children are rib fractures, especially posterior rib fractures, scapular fractures, sternal fractures, fractures of the spinous processes, and metaphyseal lesions.² Clavicular fractures and long bone fractures in children older than 1 year of age are common traumatic injuries of childhood.