Measurement of range of motion (goniometry)
To accurately determine the range of motion in joints, a joint goniometer is used. The main rule of measurement is that the axis of the device must strictly coincide with the axis of rotation of the joint, and its arms are placed along the longitudinal axes of the limb segments.
Features of measurement on the upper limb:
- Shoulder joint: when assessing abduction, the stationary arm of the goniometer is positioned vertically along the spine, and the moving arm along the axis of the humerus. Flexion and extension (in the sagittal plane) are measured with the stationary arm positioned along the trunk.
- Elbow joint: the axis of the device is set on the lateral epicondyle of the humerus, and the branches are directed along the humerus and radius.
- Wrist joint: flexion and extension are assessed using the lateral surface of the forearm and the metacarpal bone as landmarks, while adduction and abduction are measured along the dorsal surface of the hand.
Features of measurement on the lower limb:
- Hip joint: during flexion (patient supine), the axis is located on the greater trochanter. To accurately detect flexion contracture, the Thomas test is used: the healthy leg is maximally flexed and pressed to the abdomen, which blocks compensatory lumbar lordosis. Abduction is assessed by connecting the anterior superior iliac spines with a line.
- Knee joint: the lateral femoral condyle serves as the landmark.
- Ankle joint: the neutral position is considered to be the foot set at a 90-degree angle. The goniometer axis is projected onto the lateral malleolus.
Assessment of muscle strength and gait biomechanics
In addition to the range of motion, an important criterion for limb function is muscle strength. It is graded on a six-point scale:
- 5 points — normal muscle function, ability to overcome strong external resistance.
- 4 points — full range of motion, but with slight additional resistance.
- 3 points — muscles can overcome only the weight of the limb itself.
- 2 points — contraction is palpable, but there is no movement in the joint.
- 1 point — deep paresis, only isolated fiber twitches are noticeable.
- 0 points — complete paralysis, no contractions.
Static platforms are used to assess patient stability. Statodynamic gait characteristics are investigated using equipment that records step duration, rhythm, width, foot rotation angle, and load distribution across different parts of the foot.
Clinical signs of bone fractures
All fracture symptoms are divided into two large groups: definitive (absolute) and indirect (relative).
Definitive signs directly indicate a fracture. The presence of even one of them is sufficient for an accurate diagnosis:
- Deformity of the bone axis and change in segment length.
- Pathological mobility where there is normally no joint.
- Crepitus (crunching) of bone fragments rubbing against each other.
- Visualization of fragments in the wound during an open injury or their clear palpation beneath the skin.
Most important rule of traumatology: it is strictly forbidden to artificially provoke crepitus or test for pathological mobility! These actions traumatize soft tissues, can damage neurovascular bundles, and increase bleeding and pain shock. These symptoms should only be detected spontaneously when repositioning the patient or applying a splint.
Indirect signs can accompany contusions, inflammation, or hematomas. Diagnosis based on them is made only in combination. These include local pain (including upon axial loading), edema, functional impairment, skin discoloration, hematomas, phlyctenules (epidermal blisters), and body asymmetry due to a forced posture.
Symptoms of dislocations and major anatomical landmarks
Dislocations and fracture-dislocations are characterized by specific manifestations: the springy resistance sign upon attempted movement, accumulation of effusion or blood in the joint (hydrarthrosis, hemarthrosis), and gross joint symmetry disruption.
To assess the correct relationship of bone structures, traumatologists use classical anatomical lines and triangles:
- Hueter's line: passes through the epicondyles of the humerus, normally strictly perpendicular to the axis of the arm.
- Hueter's triangle: formed by the epicondyles of the humerus and the olecranon. With the elbow straightened, these three points align in a straight line. When flexed to 90 degrees, they form an equilateral triangle.
- Roser-Nélaton line: connects the ischial tuberosity with the anterior superior iliac spine. Normally, the tip of the greater trochanter of the femur lies precisely on this line.
- Schumacher's line: connects the tip of the greater trochanter with the anterior superior iliac spine.
Briefly: answers to topical questions
What are the radiological signs of bone fractures?
Radiological signs depend on the type of injury:
- In a diaphyseal fracture, the fracture line is clearly visualized.
- Displacement of bone fragments and shortening of the limb segment are characteristic.
- For stress fractures, cortical radiolucency, periosteal reaction, endosteal or cortical thickening are described; the fracture line is rarely detected.
- In the advanced phase of diabetic osteoarthropathy, fractures with disruption of the cortical layer are a mandatory sign.
What standard projections are mandatory for radiography of long tubular bones?
Radiography of long tubular bones requires imaging in two mutually perpendicular projections.
- Anteroposterior projection — standard direct view.
- Lateral projection — performed perpendicularly to the first.
A crucial rule when examining long tubular bones is the mandatory inclusion of adjacent joints (in fractures of the leg or forearm, both adjacent joints are examined). If necessary, 45° rotation projections and special atypical projections are used.
What types of bone fragment displacement are distinguished in fractures?
Fractures feature primary and secondary bone fragment displacements, which are divided into several variants.
- Displacement widthwise (transverse displacement) — graded from 0 to III depending on the preservation of fragment contact.
- Angular displacement — diagnosed by the deformity of the segment axis.
- Rotational displacement — characteristic of spiral fractures.
- Displacement lengthwise (overriding) — occurs with overlapping fragments or diastase formation.
- Impaction — a variant of lengthwise displacement with minimal displacement in spongy bone areas.
What clinical symptoms are characteristic of joint dislocations?
Joint dislocations are characterized by specific clinical symptoms associated with changes in limb anatomy and function.
- Springy resistance sign — elastic resistance when attempting to passively move the limb out of its forced position.
- Empty joint sign — depression at the usual location of the articular end.
- Axis and length alteration — disruption of the limb axis and a change in its relative length (most commonly shortening).
- Movement impairment — absence of active movements and severe restriction of passive movements.
- Palpatory findings — the articular end is palpable in an atypical location.
An accumulation of fluid in the joint (hydrarthrosis) and asymmetry of external landmarks may also be detected.
What are the basic rules for performing radiographs when a fracture is suspected?
To avoid diagnostic errors when a fracture is suspected, the following rules for taking radiographs must be strictly observed:
- Two projections — the examination is performed in two mutually perpendicular projections (anteroposterior and lateral).
- Proper positioning — strict adherence to the standard position of the patient and the examined segment.
- Centering — the injured area must be located strictly in the center of the image.
- Including adjacent joints — when examining long tubular bones, adjacent joints must be visible on the image (for fractures of the lower leg or forearm, both adjacent joints).
- Image quality — the bone tissue structure must be clearly visualized.
To remember the difference between the pelvic lines: the Röser-Nélaton line starts from the ischial tuberosity, while Schumacher's line starts from the apex of the greater trochanter (s)
Class and exam questions
Can a fracture be diagnosed solely based on swelling and severe pain?
No, swelling and pain are indirect signs that can also occur with a severe contusion. To make a diagnosis without an X-ray, it is necessary to identify definitive signs or a combination of indirect signs.
Why is it forbidden to deliberately check for bone fragment crepitus?
This causes additional severe tissue trauma, provokes intense pain, increases bleeding, and can lead to injury of peripheral nerves and blood vessels.
What is the axial load sign?
This is the appearance of localized tenderness at the site of the suspected fracture upon light percussion along the longitudinal axis of the injured bone.
What else to study on this topic
- Features of measuring the normal range of motion in spinal joints
- Specific movements in the subtalar joint: pronation and supination
- Analysis of statodynamic parameters on a platform for foot pathologies
- Differential diagnosis of indirect signs of fractures and inflammatory diseases
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