Musculoskeletal assessment

CHAPTER 10 Musculoskeletal assessment

Chapter contents

Section 10A: Orthopaedic assessment of the lower limb

1. Introduction

2. Terms of reference

3. Why is an orthopaedic assessment indicated?

4. Non-weightbearing examination

5. Foot and ankle examination

6. Limb length inequality

Section 10B: Functional assessment

1. Introduction

2. Principles of assessment

4. Observation – gait

5. Weightbearing static evaluation

6. Examination – quasi-functional and non-weightbearing

7. Secondary features

Section 10A Orthopaedic assessment of the lower limb

Introduction

A thorough musculoskeletal assessment of the whole limb is an essential component of evaluation of a patient’s specific and often localised lower limb complaint. Apparent localised foot and ankle problems may have a genesis in proximal regions or, conversely, have secondary untoward effects on other structures. Such an assessment involves both static and dynamic assessment of musculoskeletal function.

Movement of the lower limb involves interaction between the musculoskeletal and nervous systems. The function of both systems can be compromised by vascular pathology. This chapter concentrates on the orthopaedic assessment of the musculoskeletal system. The assessment of the vascular system is covered in Chapter 6 and the neurological basis of movement and assessment of the nervous system are covered in Chapter 7. As the healthcare practitioner becomes competent, experienced and confident, essential components of these three systems will be evaluated seamlessly during the patient evaluation. Although reference is made to the weightbearing examination during this chapter, this subject, including gait analysis, is covered in greater detail in section 10B (functional assessment).

The assessment process begins with a detailed history of the patient’s complaint. Subsequent examination of the limbs is based on an approach following the methodology outlined by McRae (2004):

• general observation of the patient

• specific joint observation

• examination of movements

• performance of specific tests.

Qualitative, semiquantitative and quantitative measurement techniques are used. The practitioner should be aware of the likely errors that can ensue from such measurements and take these into consideration when interpreting and analysing data from the assessment (see Ch. 4).

Terms of reference

The body is divided into three cardinal planes (Fig. 10A.1):

• frontal (coronal)

• transverse.

Figure 10A.1 Cardinal planes of the body: sagittal, frontal and transverse. Sagittal divides the body into right and left halves, frontal divides the body into front and back, and transverse divides the body into upper and lower sections. The diagram shows midplanes but the terms refer to any plane parallel to the appropriate midplane.

These planes form the reference points from which are described:

• the position of a part of the body

• joint motion

• the position of a joint

• deformity of a part of the body.

Universal use of these terms of reference is important when communicating with colleagues as one can be safe in the knowledge that they will understand the nature of the pathological process being described.

The position of a part of the body

The cardinal body planes are used as reference points to describe positions within the body:

• Anterior (to the front of) and posterior (to the rear of) describe positions in the frontal plane, e.g. the patella, or knee cap, lies anterior to the main weightbearing part of the knee joint (tibio-femoral).

• Distal (away from the centre) and proximal (towards the centre) describe positions in the transverse plane, e.g. the interphalangeal joints of the foot (IPJs) lie distal to the metatarsophalangeal joints (MTPJs) of the foot.

• Medial (towards the midline of the body) and lateral (away from the midline of the body) describe positions in the sagittal plane, e.g. the navicular lies on the medial side of the foot and the cuboid on the lateral side.

• In the foot, dorsal is used to refer to the top of the foot and plantar to the sole of the foot. The equivalents in the hand are dorsal and palmar.

Joint motion

Sagittal plane

Motion in the sagittal plane produces extension and flexion. The terms used to describe sagittal plane motion in the foot are slightly different from those used to describe such motion at the hip and knee (extension and flexion).

At the ankle (Fig. 10A.2), the midtarsal joints (MTJs), the MTPJs and the IPJs, sagittal plane motion is termed dorsiflexion and plantarflexion. Dorsiflexion denotes a raising of the whole or part of the foot towards the leg, whereas plantarflexion denotes the movement of the dorsal aspect of the foot away from the leg.

Figure 10A.2 Sagittal plane motion at the ankle. A Dorsiflexion: movement of the foot toward the anterior aspect of the tibia B Neutral position. C Plantarflexion: movement of the foot away from the tibia.

Frontal (coronal) plane

Motion in the frontal plane produces abduction and adduction of the thigh and leg and inversion and eversion of the foot. This is because the foot lies at right angles to the leg, so the terms used to describe movements of the foot differ from those used for the leg and thigh.

Abduction is when the distal segment moves away from the midline of the body and adduction when it moves towards the midline. For example, in order to do the ‘splits’, gymnasts must abduct their legs. Inversion of the foot is when the plantar aspect of the foot is tilted so as to move towards the midline of the body. Eversion is when the plantar aspect of the foot is tilted so as to face away from the midline of the body (Fig. 10A.3).

Figure 10A.3 Frontal plane motion in relation to the midline of the body (black line). A Inversion: the foot is lifted up and away from the line. B Eversion: the foot is moved down and towards the line.

Transverse plane

Motion in the transverse plane produces internal and external rotation of the thigh and leg and adduction and abduction of the foot.

Internal rotation occurs when the anterior surface of the distal segment rotates medially in relation to the proximal segment and external rotation when the opposite occurs – the anterior surface of the distal segment moves laterally in relation to the proximal segment (Fig. 10A.4).

Figure 10A.4 Relationship between transverse plane motion in the leg and transverse plane motion in the foot. A The feet are mildly abducted; this is the normal standing position B The legs are externally (laterally) rotated, which results in abduction of the feet (C). D The legs are internally rotated (medially), which results in the adduction of the feet (E).

In the foot, the use of the terms adduction and abduction depends upon the site of the reference point: the midline of the body or the midline of the foot. Functionally, the midline of the body is usually used as the reference point:

• Abduction of the foot is when the distal part of the foot moves away from the midline of the body

• Adduction when the distal part of the foot moves towards the midline of the body (Fig. 10A.4).

The mid-axial line of the forefoot is different from that of the hand. For the latter, the middle finger is taken as the mid-axial point. Muscles which abduct (dorsal interossei) and adduct (palmar interossei) the fingers take the middle finger as their reference point. Conversely in the foot the longitudinal axis has shifted pre-axially and the second toe becomes the reference point for the mid-axial line for the actions of the dorsal and plantar interossei. The adductor hallucis is inserted into the lateral side of the proximal phalanx of the hallux and is so termed because it brings about adduction of the hallux – movement of the hallux towards the midline of the foot.

Triplanar motion

The position of the joint axis together with the shape of the articulating surfaces can result in motion in more than one plane for a joint or combination of joints acting together.

If a joint axis is positioned at an angle of less than 90° to all the cardinal body planes triplanar motion can occur, e.g. pronation and supination:

• Pronation is the collective term for dorsiflexion, eversion and abduction.

• Supination is the collective term for plantarflexion, inversion and adduction.

For example, in the foot triplanar motion occurs at the subtalar and midtarsal joints.

Position of a joint

To describe the position of a joint the suffix ‘-ed’ is used:

• Sagittal plane – extended and flexed (thigh and leg); dorsiflexed and plantarflexed (foot)

• Transverse plane – internally and externally rotated (thigh and leg); adducted and abducted (foot)

• Frontal plane – abducted and adducted (thigh and leg); inverted and everted (foot)

• Triplanar – pronated and supinated (foot).

It is important that a distinction is made between joint motion and position; a joint may be moving in the opposite direction to the position it occupies at any one moment. For example, at heel-strike the foot is slightly supinated (position) but as soon as the heel contacts the ground pronation (motion) occurs at the subtalar joint (STJ) in order to absorb shock from ground contact.

Deformity of a part of the body

The term ‘deformity’ is used to describe an abnormal position adopted by a part of the body.

Terms used to denote deformity often have the suffix -us:

• Sagittal plane – equinus is when the foot or part of the foot is plantarflexed, e.g. ankle equinus, and extensus is when the foot or part of the foot is dorsiflexed, e.g. hallux extensus. Calcaneus is used to describe the calcaneus when it is in fixed dorsiflexion, e.g. talipes calcaneovalgus.

• Frontal plane – varus and valgus (Fig. 10A.5).

• Transverse plane – adductus or abductus.

Figure 10A.5 Frontal plane deformity of the legs. A Genu valgum (knock knees): the knees are close together and the medial malleoli are far apart. B Genu varum (bow legs): the knees are far apart and the medial malleoli are close together.

To reinforce the importance of understanding these terms, Figure 10A.6 illustrates the three planes of a knee as seen on a plain radiograph and Figure 10A.7 illustrates the three planes of the ankle and hindfoot as seen on magnetic resonance imaging (MRI).

Figure 10A.6 Plain X-ray views of a knee joint: A anteroposterior or frontal (coronal) view; B lateral or sagittal view; C and skyline (axial) or transverse view, demonstrating patello-femoral position.

Figure 10A.7 MRI of ankle and hindfoot: A anteroposterior or frontal (coronal) view; B lateral or sagittal view; and C axial or transverse view.

Why is an orthopaedic assessment indicated?

Normal lower limb function should be free of pain and energy efficient. The main purpose of the orthopaedic assessment is to identify whether the system is functioning within the boundaries of ‘normality’. Normal function can be affected by many factors (Box 10A.1). It should be remembered that orthopaedic lower limb problems are not always isolated in origin. They may result from referred pain from a proximal source or can be part of a systemic disorder, e.g. a neuromuscular disease. It is therefore important that the lower limbs are not examined in isolation and that observation and examination of other parts of the body are undertaken where indicated.

Box 10A.1 Factors that can affect normal function

• Hereditary/congenital problems, e.g. Charcot–Marie–Tooth disease, talipes equinovarus, developmental dysplasia of the hip (DDH)

• Acute/chronic injury causing pain, e.g. slipped capital femoral epiphysis, ankle sprain

• Abnormal alignment secondary to trauma, e.g. femoral/tibial/epiphyseal fracture

• Abnormal alignment (developmental), e.g. internal femoral torsion, genu valgum

• Infections, e.g. tuberculosis

• Neurological disorders, e.g. cerebrovascular accident

• Muscle disorders, e.g. Duchenne’s muscular dystrophy

• Neoplasia, e.g. osteosarcoma

• Systemic disease, e.g. autoimmune (rheumatoid arthritis), bone disease (Paget’s disease)

• Degenerative processes, e.g. osteoarthritis

• Joint hypermobility, e.g. Marfan’s syndrome

• Osteochondroses, e.g. Perthes’ disease

• Psychological factors, e.g. attention seeking

• Footwear, e.g. high-heeled shoes

In summary the purpose of an orthopaedic lower limb assessment is to:

• establish the main complaint(s), e.g. pain, stiffness, tenderness, numbness, weakness, crepitus

• identify the site of the primary problem, e.g. foot, leg, knee, hip, and try to relate to underlying structures

• identify any secondary problems and relate them to the primary problem, e.g. lesion patterns, pronation due to leg-length discrepancy

• identify the cause of the problem, e.g. abnormal alignment

• establish how the problem evolved

• identify any movement/activity that produces/exacerbates symptoms

• identify movement/activity that relieves symptoms

• establish any differential diagnoses

• utilise the data from the assessment to produce an effective management plan

• utilise the data from the assessment to monitor the progress of the condition.

The assessment process

When undertaking an assessment of the lower limb it is essential that the system is observed weightbearing (dynamic and static) and non-weightbearing. Differences between the two states can help to determine whether compensation has occurred. For example, non-weightbearing assessment may identify the presence of a forefoot varus; observation of the patient’s gait may show this problem has been fully compensated through abnormal positioning of the STJ. Conversely, information from the non-weightbearing assessment may explain the cause of a gait abnormality, e.g. a patient may have a bouncy gait due to an early heel lift; non-weightbearing assessment of the ankle joint may reveal that the cause is an ankle equinus secondary to a short gastrocnemius muscle.

To gain a full and detailed picture of the function of the locomotor system, the following factors must be assessed:

• alignment and position of the lower limb

• joint motion

• muscle action.

The sequence of assessment of the above varies among practitioners. There is no one correct sequence; practitioners should adopt the sequence and approach they feel most comfortable with. However, it is essential that a systematic approach is adopted to ensure vital pieces of data are not omitted. For complete assessment, the examination should involve the following three important sections:

1. Non-weightbearing. This will focus on the assessment of joints and muscles.

2. Gait analysis. This will focus on the position and alignment of the body and foot–ground contact during dynamic weightbearing.

3. Static weightbearing. This will focus on the position and alignment of the body and the relationship of the foot to the ground during stance.

Areas 2 and 3 are covered in greater detail in section 10B.

For successful assessment, it is important that the patient is at ease and cooperates with and has confidence in the practitioner. The practitioner should always be sensitive to the patient’s needs and explain what they are about to do and why, before undertaking the assessment. Qualitative and quantitative measurement should be undertaken where necessary, but the data must be meaningful and reproducible if they are to be of any use in assessing improvement or deterioration. Various measuring devices may be used; their use will be discussed in the appropriate sections.

General assessment guidelines

• Always observe and functionally assess the joints bilaterally.

• It is valuable to obtain an overview of both limbs, particularly if the onset of the problem is insidious, the pain is diffuse and nonspecific or if during testing a number of joints seem to be implicated.

• Where only one limb is affected, it is often helpful to start with the unaffected limb first, then repeat the test on the affected limb. Compare ranges of motion, end feel (the sensation the examiner feels when they push the joint being examined to the end of its range of motion) and muscular strength.

• It is helpful to arrange your testing so that the most painful test is last. This ensures that the condition will not be aggravated by your testing procedure or make the patient apprehensive.

Not all the tests will be required during every lower-limb assessment. The selection of tests used will depend on the findings as the examination proceeds, and should be influenced by the preceding clinical history and observations. However, it is necessary to be thorough enough to rule out alternative pathologies. The exclusion of alternative aetiologies may require the assessment of additional systems, e.g. the cardiovascular system. Referred pain associated with local nerve entrapment or radicular patterns of pain in which spinal nerves or nerve roots are irritated need to be considered.

Remember that a problem that affects one part of the system can lead to problems elsewhere in the system. The lower limb functions as one mechanical unit and as a result a problem in one part may have to be compensated for in another part of the system. Compensation is a change in the structure, position or function of one part in an attempt to adjust to an abnormal structure, position or function in another part. For example, scoliosis of the spine may lead to an apparent leg-length discrepancy, which will affect foot function. Conversely, a problem affecting the foot, e.g. an uncompensated rearfoot varus, may lead to discomfort/pain at the knee.

The process of assessment follows a standard format:

• General observation of the patient

• Specific joint observation

• Examination of joint movement

• Muscle assessment

• Undertaking special tests

• Arranging further investigations.

General observation of the patient

The assessment process starts at the time of introduction. Observation of a patient’s demeanour, facial expression, seated posture and how they get up from a chair provides valuable clinical information. In addition, the way in which the patient walks into the clinic, together with use of walking aids, provides more information about mobility and how this might be influencing lower limb/foot function. After history taking, the patient will have to undress appropriately. Observation of the ease with which this is achieved gives an insight into the way a patient copes with certain activities of daily living.

Specific joint observation

Observation of each lower-limb joint before the examination will establish the presence of any clinical features synonymous with pathology, e.g. oedema, contusion, erythema, local muscle wasting, alteration in shape or the presence of scars. Symmetry of contralateral parts, abnormal posture/evidence of limb shortening and abnormal joint movement during gait are additional clinical clues to underlying pathology.

Palpation

Palpation of the limb segment or joint for clinical features such as raised/lowered skin temperature, swelling/effusion, tenderness, pain or abnormal lumps/nodules also provides information to help establish a diagnosis.

Examination of joint movement

Features of an inflamed joint are redness (rubor), heat (calor), pain (dolor), swelling (tumour) and loss of function. Inflammation of a joint may be due to a range of factors, e.g. trauma, arthritis and infection. Examination of the joint, information from the medical and social history and results of radiological and laboratory investigations will enable a diagnosis to be made. If a patient complains of a painful joint, the characteristic features of the pain should be recorded.

Before examining a joint, it is helpful to ask the patient to move the affected limb to assess the likely range of pain-free movement. The process of joint assessment should include the following:

• Range of motion (ROM)

• Direction of motion

• Quality of motion

• Symmetry of motion

• Absence/presence of deformity, including dislocation and subluxation.

ROM is the amount of motion at a joint and is usually measured in degrees. The ROM at a joint can be compared with the expected ROM for that joint, e.g. if only 20° of motion occurs at the first MTPJ when the expected norm is 70° (28% of the normal ROM) it can be concluded that the ability of this joint to carry out normal function is impaired (hallux limitus). Often a guesstimate of the amount of joint motion is made from observation. Protractors, tractographs and goniometers can be used to quantify joint motion (Fig. 10A.8).

Figure 10A.8 Devices used to measure joints. A Protractor. B Tractograph. C Finger goniometer. D Gravity goniometer.

A joint may show normal ROM but the direction of the motion may be abnormal. It is, therefore, important to note the direction as well as the range. For example, the total ROM of transverse plane rotation at the hip is 90°; 45° internal rotation and 45° external rotation. If the ROM is 90° but there is 70° of external rotation and 20° of internal rotation then the ROM would be normal but the direction of the motion would be abnormal. Normal joint motion should occur without crepitus, pain or resistance (quality of motion). The ROM and direction of motion of a joint, e.g. hip, should be the same for both limbs (symmetry of motion). The presence of asymmetry of motion should always be noted.

Joint motion can be affected by the ligaments around the joint. It is important as part of joint assessment to identify any dysfunction of the ligaments, e.g. ligament tear or rupture. Finally, joints should be assessed as to whether they are subluxated or dislocated. Dislocation occurs where there is no contact between articulating surfaces of the joint and subluxation where there is only partial contact.

The range of active and passive movement of each respective lower limb joint should be examined, documented, and compared with the contralateral side. It is useful to assess whether passive movement of the joint provokes any pain or guarding (sometimes seen in hallux limitus). In addition, it is valuable to document the response to resisted testing (strong/weak/painless/painful) and stability of the joint. This will determine the integrity of the articulating surfaces and ligaments. Provoking crepitus on joint movement is an indication of joint damage.

Muscle assessment

Muscles allow active motion at joints. They should be tested for:

Strength

The Medical Research Council (MRC) system is commonly used for grading muscle strength (Crawford Adams & Hamblen 1990):

• 0 = no contraction

• 1 = a flicker from muscle fasciculi

• 2 = slight movement with gravitational effects removed

• 3 = muscle can move part against gravity

• 4 = muscle can move part against gravity + resistance

• 5 = normal power.

Muscle strength can be assessed both by the patient initiating active motion, and by the clinician attempting to prevent active motion – resisted movement.

Tone

All muscles should show tone. Asking the patient to undertake isometric contraction of a muscle is a useful means of identifying tonal quality. Tone can also be assessed by the examiner holding the limb and placing it through a range of movement. Involuntary resistance is indicative of increased tone.

Spasm

Muscles may present in spasm and as a result joint motion is affected. Information from the neurological assessment and medical history aids identification of its causation.

Bulk

Muscle bulk should be observed and comparisons made between the limbs. Atrophy of muscle results in a loss of muscle bulk and may be due to a number of factors, e.g. lack of use, lower motor neurone lesion. Hypertrophy of muscles that show normal tone and symmetrical distribution is considered normal and is usually due to exercise. Unilateral atrophy/hypertrophy can be assessed by observation and recorded by measuring the girth of both limbs with a tape measure.

Undertaking special tests

It may be necessary to carry out specific tests to confirm a diagnosis or to differentiate between similar conditions. Some clinical examination techniques have been developed to test a particular aspect of joint function, e.g. Lachman’s test to assess sagittal plane stability of the knee in an anterior direction and thereby the integrity of the anterior cruciate ligament. The section on non-weightbearing examination discusses the specific tests used to assess each of the lower limb joints and their associated structures.

Arranging further investigations

Usually the information obtained from a detailed history and assessment is sufficient to arrive at a diagnosis. Occasionally, specialist investigations may be necessary to confirm the diagnosis or to consider other options. A number of possibilities are available including: specialist imaging techniques and haematological, biochemical and nerve conduction studies and electromyography (EMG). In addition, histological examination of specimens, video/treadmill gait analysis or computerised analysis/forceplate analysis may be indicated.

Non-weightbearing examination

The prime purpose of the non-weightbearing examination is assessment of the joints and muscles of the lower limb and other important soft-tissue structures. A flat couch is required for the patient to lie on. Patients should feel comfortable and relaxed and should not be wearing restrictive clothing. Non-weightbearing examination involves an assessment of the following:

• Ankle and hindfoot

• Metatarsals

• Digits (proximal and distal IPJs)

• Alignment of the lower limb.

Examination of the hip

The hip joint is regarded as a stable ball and socket synovial joint. It has sufficient mobility to allow economic gait and stance while being more restricted than its counterpart in the upper limb, the shoulder joint (glenohumeral joint), which tolerates greater potential instability in exchange for increased motion. The hip joint’s stability is provided by:

• depth of the acetabulum, accentuated by the fibrocartilaginous labrum

• strong capsule, reinforced by capsular ligaments

• surrounding muscles.

History

Hip joint pain (coxodynia) is usually felt as an anterior groin pain sometimes radiating down the front of the thigh as far as the knee. In children, significant hip pathology may present as knee pain due to the shared nerve supply (femoral and obturator nerves).

A frequent diagnostic problem is distinguishing hip from spinal problems, and they often co-exist in elderly people. Low back pain radiating into the buttock, and posterior and lateral aspects of the thigh is more likely to have a spinal origin. Similarly proximal pain which radiates below the knee into the calf and foot is unlikely to emanate from the hip joint. A history of altered sensation or weakness in the limb is more likely to be neurological in origin. With concomitant spine and hip pathology, an intra-articular injection into the hip joint of local anaesthetic (with or without steroid in arthritic conditions) under aseptic conditions and image intensifier control can help distinguish the contribution of the hip from that of the spine.

Examination

Not every patient who presents to a podiatry clinic needs to have their hips examined. However, the hip should be examined if the patient complains of discomfort or pain in the area and/or gait analysis reveals an abnormality which affects normal pelvic and lower limb mobility and mechanics, e.g. weakness or limb discrepancy. The hip should be examined with the patient:

• lying on the examination couch

Preparation for the hip examination

A proper hip examination requires both space and exposure:

• Adequate clinic space is required to allow the patient to stand and be observed standing from all positions and to walk freely.

• The examination couch should ideally not be placed against a wall. The examiner should be free to examine the patient from both sides and be allowed unencumbered assessment of parameters such as hip abduction.

• The patient should be adequately exposed. Ideally, they should be undressed down to shorts or suitable underwear. Both the hip and spinal areas should be exposed to assess linked mobility and posture.

Patient standing

The patient should be observed standing with the spine and lower limbs exposed.

Observe the patient from all positions and look for evidence of the following:

• Wasting: Wasting particularly of the thigh and gluteal (buttock) musculature may indicate long-standing hip pathology, such as arthritis, infection and congenital disorders.

• Scars: Has the patient had previous surgery or sustained any traumatic injury? A pitted sinus may indicate previous infection, e.g. tuberculosis.

• Exaggerated lumber lordosis: This is observed from the side and, if present, may indicate a fixed flexion deformity of the hip joint.

• Limb attitude: The position of both limbs will indicate any rotational or frontal plane (abduction/adduction) gross deformities.

• Evidence of limb-length inequality: See section on limb-length inequality.

Trendelenburg’s test

This test is performed with the patient standing. The patient can be assessed from the front or behind – the latter is usually more reliable. The patient is initially asked to single leg stance on the unaffected limb. Normally the contralateral buttock is elevated and pelvis tilted towards the standing side. This moves the centre of gravity of the body closer to the centre of the standing hip joint. The pelvic tilt is produced by the hip abductors (principally gluteus medius and minimus).

The patient is asked to elevate the contralateral pelvis for 30 seconds, and then they are asked to repeat the test on the affected limb. If the contralateral hemi-pelvis cannot be elevated and held for 30 seconds the patient is said to be Trendelenburg positive. Often the patient will tilt their trunk excessively, bringing the centre of gravity close to or even lateral to the centre of the standing hip joint. A positive Trendelenburg test indicates one or more of the following problems:

• Weak abductors, e.g. in poliomyelitis, muscular dystrophies, post-surgical nerve damage

• Painful arthritic hip joint, which both inhibits gluteal activity and increases friction within the joint opposing abductor activity

• Congenital disorders, e.g. developmental dysplasia of the hip and coxa vara

• Previous injury to the proximal femur, reducing the efficiency of the gluteal system.

Patient lying on the examination couch

Ideally the patient should be able to lie fully flat on the examination couch. The examiner should be able to observe the pelvis and limb position and gain access to the lumbar spine area to assess changes in lumbar position. Usually, the examination is commenced with the patient lying supine. Check that the patient’s iliac crests on either side of the pelvis are level and that the lower limbs are placed in identical position. Begin the supine examination with an assessment of limb-length inequality (see end of section 10A).

Palpation

Ask the patient to point and demonstrate the sight of any pain. The centre of the hip joint is deep to the femoral pulse, which can usually be easily palpated. However, the hip is a far deeper joint than the knee and, subsequently, it is more difficult to palpate and has fewer landmarks. However, a systematic examination around the hip joint should include palpation of:

• anterior groin for crepitus, swelling and tenderness – remember the other causes of groin pain including herniae, varicose veins and swollen lymph nodes

• adductor tendon origin

• proximal quadriceps

• lateral structures – including the greater trochanter and gluteal area for evidence of trochanteric bursal pathology

• iliac tuberosity for proximal hamstring pathology

• piriformis tenderness – rarely related to sciatic nerve compression.

Check for evidence of previous scarring from surgery or trauma. Look for healed sinuses which may be evidence of old, deep infection. Look for evidence of wasting of the thigh musculature – indicative of disuse of the joint.

Assessment of hip joint mobility

Hip joint mobility should be assessed in three planes:

• Sagittal: extension and flexion

• Frontal: abduction and adduction

• Transverse: internal and external rotation.

Before commencing formal passive hip movements, it is wise to ask the patient to move each limb actively in turn. This allows a rapid, albeit global, assessment of the amount of pain-free movement that is likely to be available in each limb. Similarly, gently rotating the extended limb internally and externally will indicate the degree of ‘irritability’ of the joint. Pain from this gentle manoeuvre is unlikely to elicit pain from any pathology except an intra-articular problem.

Sagittal plane movement

To ensure normal forward progression during gait, sagittal plane motion at the hip is essential. There should be approximately 120–140° of flexion and 5–20° of extension, although not all of this is necessary for gait.

Hip extension and Thomas’ test

Extension of the hip is assessed by placing one of the examiner’s hands under the lumbar spine. At rest the curvature of the lower spine (lumbar lordosis) should be felt. With the hand staying in this position, ask the patient to flex the healthy hip and knee. As the hip progressively flexes, the lumbar curvature should progressively flatten until the lordosis is obliterated.

If during the process of flexing the healthy hip, the damaged hip begins to lift from the couch, the patient is said to exhibit a loss of extension or fixed flexion deformity (FFD), which can be measured in relationship to the horizontal. Many patients when standing and walking attempt to ‘mask’ moderate degrees of fixed flexion deformities by increasing their lumbar lordosis.

The test can be undertaken ‘in reverse’ by asking the patient to flex both hips and during this manoeuvre confirm that the lumbar curve has been obliterated. Then, in turn, ask the patient to hold one leg in position with their hands while gradually extending the other hip. In health, a person should be able to place the leg on the couch without increasing the lumbar lordosis as a compensatory mechanism.

If the hip displays no evidence of an FFD, more subtle changes of hip extension may be detected by placing the patient prone. With the pelvis stabilised by the examiner’s hand, each limb in turn is lifted from the couch and any difference noted. Normal extension is up to 10–20°.

Hip flexion

The good hip is flexed to allow lumber spine flattening. The comfortable flexion angle is noted and the patient asked to steady the limb with their own hands. The affected hip is then flexed while checking that the pelvis and lumber spine remain static. A comparison is made between the flexion in both hips.

The sagittal ROM is recorded. For example, with an osteoarthritic left hip, the following may be written in the notes:

• Right hip: extension 15°, flexion 120°

• Left hip: extension −30°, flexion 90°

The normal right hip has a total arc of movement of 135° while the diseased hip has only 60° with a significant FFD.

Frontal plane movement

This should be assessed with the patient lying flat and supine, with room to assess both limbs. An exaggerated impression of available hip abduction may be gained if the pelvis is not stabilised by the examiner placing their hand on the contralateral iliac crest as the limb is moved. Then the limb is moved outwards and the arc of movement from the midline noted. If possible, when dealing with unilateral pathology, start with the normal side. Usually, enough abduction is available in the healthy hip to allow the leg to hang dependent over the couch with the knee flexed. This allows further stabilisation of the pelvis and allows comparison with the contralateral side. Normal hip abduction is at least 40°.

Adduction is best assessed after abduction. Less adduction is available than abduction – usually about 25°. It can be assessed in several different ways:

• Each limb in turn can be raised and brought across the midline over the contralateral limb.

• The contralateral limb can be raised by an assistant, allowing the limb being examined to be moved in a more pure frontal plane.

• With the contralateral limb held in an abducted position, e.g. flexed at the knee over the side of the couch, move the limb being examined into the space vacated by the other limb.

Tightness of the adductors on attempted abduction is common in osteoarthritis and other common hip pathologies. In cerebral palsy, it can lead to a scissors-type gait when one or both legs have a tendency to cross over during gait.

Transverse plane movement

Internal and external hip rotation can be assessed in several different ways. The recorded measurement might be slightly different according to the method employed. It is important that the way the assessment was conducted is recorded in the notes. Essentially there are three methods:

• Supine patient with hips and knees extended

• Supine patient with knees and hips flexed

• Prone patient with hips extended and knees flexed.

With the patient supine, rotation can be assessed with the hips and knees extended, i.e. the legs straight. Observe the patient from the foot of the bed and assess rotation in each limb simultaneously. Hold each heel in the palm of your hands and first externally rotate and then internally rotate each limb. In this position, rotation is derived from the hip, unless there is any knee instability. It is useful to observe the movement of the patellae as a gauge of the amount of rotation from the hip. The alternative method with the patient supine is to flex to 90° the hip and knee joints. This may be difficult if hip flexion is painful and restricted. The hip is moved both internally and externally and the angle is measured by comparing the position of the shin with respect to the midline.

With the patient prone, rotation can be assessed by flexing the knees to 90°. The legs can be simultaneously rotated outwards to assess and compare internal rotation. External rotation can be assessed with one limb extended and the other leg moved towards the midline. Alternatively, external rotation can be compared by crossing the legs. For all these manoeuvres it is important that rotation is not exaggerated by the pelvis lifting alternatively off each side.

In health, 45° of comfortable internal and external rotation is possible. In certain conditions, e.g. unilateral excessive femoral anteversion, the total rotational arc may be the same in both hips, but with a skew in one rotational direction in one hip compared to the other. Females tend to show more internal rotation than males (Svenningsen et al 1990). The range of transverse plane motion at the hip decreases with age and most hip pathologies.

Assessment of femoral anteversion

Femoral anteversion is the angle that the femoral neck makes with the shaft of the femur. It varies with age, and there is a difference between the sexes. In males, the neck lies more in line with the femoral shaft than in females – 140° compared with 120° of anteversion. In children, the angle is similar to that in the adult female. It is important for podiatrists to be aware of this because excessive femoral anteversion is one of the most important causes of ‘intoeing’ – especially in the child (along with tibial internal torsion and persistent metatarsus adductus).

The most accurate clinical evaluation of femoral anteversion is with the patient lying prone and the knee flexed. With the contralateral limb extended, rotate the leg from side to side. Feel the greater trochanter laterally as the hip rotates. When the trochanter is truly facing lateral, the angle between the shin position and the vertical represents the anteversion angle of the femoral neck. On occasions, computed tomography (CT), which can measure this angle more accurately, is required.

Patient walking

Ask the patient to walk up and down the examination area. Make sure that there are no obstructions and the patient can perform at least four to five stride lengths. With regard to hip pathology, the four most common reasons why a patient has a limp are:

• pain – an antalgic gait pattern

• weakness – e.g. abductor weakness causing Trendelenburg’s gait pattern

• limb-length inequality

• deformity – e.g. adduction or rotational deformity.

Patients often display one or more of these problems. A thorough examination of the patient on the examination couch will have flagged up likely gait problems, e.g. limb shortening and significant hip pain on motion.

Imaging of the hip joint

X-rays

Conventional radiographic views of the hip joint includes an AP view of the pelvis (Fig. 10.9) and a lateral view of one or both hip joints. The advantage of the pelvic AP view is that the hips can be compared and any other pathology within the bony pelvis can be noted, e.g. Paget’s disease. Other views can be requested under specific circumstances but are beyond the scope of this discussion.

Figure 10A.9 AP pelvis radiograph showing an osteoarthritic hip.

Magnetic resonance imaging

MRI can be used to look for subtle pathology within the hip joint, e.g. labral cartilage tears. Additionally, it allows visualization of the extra-articular soft tissues and may detect conditions that cause hip/groin pain, e.g. bursitis. MRI can also show subtle osseous lesions, for instance early avascular necrosis.

Computed tomography

CT can be useful for looking at bone and joint structure and disease. Modern CT scanners with the ability to collect increasingly smaller, thin slices of information, are capable of detecting ever more subtle lesions. In addition, the ability to reformat the information into a three-dimensional image has helped our understanding of musculoskeletal pathology and planning of corrective procedures.

Isotope scanning

Scanning with isotopes such as technetium-99m is a useful way of determining the presence or absence of pathology in the region of the hip joint. It is helpful in distinguishing the location of discomfort, e.g. hip joint pathology versus spine. It is sensitive for identifying areas of inflammation and abnormal pathology while not being particularly specific about the cause. It is particularly useful in assessing whether an established hip replacement is beginning to loosen and causing symptoms.

Knee examination

The knee joint is a complex synovial joint and should be considered as having three parts:

• Patellofemoral joint

• Medial tibiofemoral joint

• Lateral tibiofemoral joint.

History

A thorough assessment of a knee joint problem requires information about several key issues.

Background information

Knowledge of many background features is important:

• Previous injuries and/or surgery to the knee

• Previous treatment to the joint, e.g. medications, physiotherapy

• Sport(s) and occupation(s) of the patient

• Future activity aspirations of the patient.

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Tags: Merrimans Assessment of the Lower Limb

Aug 10, 2016 | Posted by admin in PHYSICAL MEDICINE & REHABILITATION | Comments Off

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