Gait

Original Editor - Karsten De Koster Top Contributors - Lauren Heydenrych, Lucinda hampton, Kim Jackson, Nikhil Benhur Abburi, Admin, Alexandra Kopelovich, Vidya Acharya, Shaimaa Eldib, Rishika Babburu, Maarten Cnudde, Ahmed M Diab, Khloud Shreif, Ayesha Arabi, Rucha Gadgil, Simisola Ajeyalemi, Tolulope Adeniji, WikiSysop and Janine van Dyk

Introduction

Gait is defined as the walking pattern in humans. It is further described as particular manner of moving on foot which can be a walk, jog or run.

Human gait depends on a complex interplay of major parts of the nervous, musculoskeletal and cardiorespiratory systems.

• The individual gait pattern is influenced by age, personality, mood and sociocultural factors.
• The preferred walking speed in older adults is a sensitive marker of general health and survival.
• Safe walking requires intact cognition and executive control.
• Gait disorders lead to a loss of personal freedom, falls and injuries and result in a marked reduction in the quality of life. 

Definitions

Ambulation: Refers to a type of locomotion in a broad sense. It is more often used in the clinical sense of describing whether or not someone can walk freely or with the assistance of some device.

Walking: A particular form of gait and the most common of human locomotor patterns.

The demarcation between walking and running occurs when periods of double support during the stance phase of the gait cycle (both feet are simultaneously in contact with the ground) give way to two periods of double float at the beginning and the end of the swing phase of gait (neither foot is touching the ground).

Gait cycle: "The basic unit to characterise the way of walking, assuming that successive cycles will be reasonably similar if not the same."

• This cycle is typically made up of 2 phases, namely stance and swing phase.
• The cycle begins with one foot touching the ground and ends with the same foot touching the ground again.

Gait Analysis: A "broad spectrum of potential assessment strategies used to evaluate normal and abnormal gait."

Gait Speed: The time it takes to walk a specified distance, usually 6m or less. Slower speeds correlate with an increased risk of mortality in geriatric patients.

• Normal walking speed primarily involves the lower extremities, with the arms and trunk providing stability and balance.
• Faster speeds - body depends on the upper extremities and trunk for propulsion, balance and stability with the lower limb joints producing greater ranges of motion.

Step length: the distance between the point of initial contact of one foot and the point of initial contact of the opposite foot.

Stride length: The interval between sequential initial floor contacts by the same limb.

Step time: The time between heel strike of one leg and heel strike of the contralateral leg.

Step width: The mediolateral space between the two feet

Clinical Application

Understanding the gait cycle allows for effective gait analysis. When analysing gait, it should be done systematically, looking at each joint separately throughout the entire gait cycle and detecting deviations from normal. Injury or disease can alter any of the sub-phases of the gait cycle, resulting in distinct changes to the characteristics of the gait pattern.

Gait Analysis

• An analysis of each component of ambulation is an essential part in the diagnosis of various neurological disorders. It is also important in the assessment of patients during the process of rehabilitation and recovery from the effects of neurological disease, musculoskeletal injury, disease progress or amputation of a lower limb.
• Gait assessments may evaluate walking and running.
  • Gait assessments range from simple observations (clinical gait assessments) to computer analysis of biomechanics and spatiotemporal parameters, termed instrumental gait analysis (IGA).

Quantitative and qualitative approaches

An objective approach is quantitative, and parameters like time, distance, and muscle activity will be measured. Objective methods which use equipment to assess gait include:

• Video Analysis and Treadmill
• Electronic and Computerized Apparatus
• Electronic Pedometers
• Satellite Positioning System

Qualitative methods to assess and analyse gait include:

• Rancho Los Amigos Hospital Rating List
• Ten Meter Walking Test
• 6 Minute Walk Test
• 2 Minute Walk Test
• Dynamic Gait Index
• Emory Functional Ambulation Profile
• Timed Up and Go Test This test is statistically associated with falling in men, but not in women.
• Functional Ambulation Categories
• Tinetti-Test

Further explanations of gait range, muscle use and the ground reaction force (GRF)

Gait Disturbances

Gait disturbances are any deviations from typical walking or gait.

Identification is important because gait disturbances can lead to a loss of personal freedom and to reduced quality of life. In addition they can be precursors of falls and therefore of potentially severe injuries in elderly persons.

Causes of Gait Disturbances/Disorders

Gait disturbances include neurological, orthopedic, medical and psychiatric conditions. Multifactorial etiology becomes more common with advancing age, making classification and management more complex. Any gait disturbance should be thoroughly investigated in order to improve patient mobility and independence, to prevent falls and to detect the underlying causes as early as possible.

Thorough clinical observation of gait, careful history taking focused on gait, falls and physical, neurological and orthopedic examinations are basic steps in the categorisation of gait disturbances and serve as a guide for ancillary investigations and therapeutic interventions.

Musculoskeletal Causes

Pathological gait patterns resulting from musculoskeletal are often caused by soft tissue imbalance, joint alignment or bony abnormalities.

Hip Pathology

• Arthritis is a common cause of pathological gait. An arthritic hip has reduced range of movement during swing phase which causes an exaggeration of movement in the opposite limb ‘hip hiking.
• Excessive Hip Flexion can significantly alter gait pattern most commonly due to;
  • Hip flexion contractures
  • Iliotibial (IT) band contractures
  • Hip flexor spasticity
  • Compensation for excessive knee flexion and ankle dorsiflexion
  • Hip pain
  • Compensation for excess ankle plantar flexion in mid swing.
    • The deviation of stance phase will occur mainly on the affected side. The result is forward tilt of the trunk and increased demand on the hip extensors or increased lordosis of the spine with anterior pelvic tilt. A person with reduced spinal mobility will adopt a forward flexion position in order to alter their centre of gravity permanently during gait.
• Hip Abductor Weakness. The abductor muscles stabilise the pelvis to allow the opposite leg to lift during the swing phase. Weak abductor muscles will cause the hip to drop towards the side of the leg swinging forward. This is also known as Trendelenburg gait
• Hip Adductor Contracture. During swing phase the leg crosses midline due to the weak adductor muscles, this is known as ‘scissor gait’
• Weak Hip Extensors will cause a person to take a smaller step to lessen the hip flexion required for initial contact, resulting in a lesser force of contraction required from the extensors. Overall gait will be slower to allow time for limb stabilisation. Compensation is increased posterior trunk positioning to maintain alignment of the pelvis in relation to the trunk
• Hip Flexor Weakness results in a smaller step length due to the weakness of the muscle to create the forward motion. Gait will likely be slower and may result in decreased floor clearance of the toes and create a drag

Knee Pathologies

• Weak Quadriceps. The quadriceps role is to eccentrically control the knee during flexion through the stance phase. If these muscles are weak the hip extensors will compensate by bringing the limb back into a more extended position, reducing the amount of flexion at the knee during stance phase. Alternatively heel strike will occur earlier increasing the ankle of plantar flexion at the ankle, preventing the forward movement of the tibia, to help stabilise the knee joint.
  • Severe Quadriceps Weakness or instability at the knee joint will present in hyperextension during the initial contact to stance phase. The knee joint will ‘snap’ back into hyperextension as the bodyweight moves forwards over the limb

• Knee Flexion Contraction will cause a limping type gait pattern. The knee is restricted in extension, meaning heel strike is limited and step length reduced. To compensate the person is likely to ‘toe walk’ during stance phase. Knee flexion contractures of more than 30 degrees will be obvious during normal paced gait. Contractures less then this will be more evident with increased speeds. 
  

Ankle Pathologies

• Ankle Dorsiflexion Weakness results in a lack of heel strike and decreased floor clearance. This leads to an increased step height and prolonged swing phase. 
• Calf Tightening or Contractures due to a period of immobilisation or trauma will cause reduced heel strike due to restricted dorsiflexion. The compensated gait result will be ‘toe walking’ on stance phase, reduced step length, and excessive knee and hip flexion during swing phase to ensure floor clearance.
  

Foot Pathologies

• Hallux Rigidus results in a lack of dorsiflexion of the great toe.  The MPJ uses the windlass effect to raise the arch and stiffen the foot during dorsiflexion of the hallux. This stiffness increases the efficiency of the propulsion portion of the gait cycle. To be efficient in creating stiffness, the hallux should be able to dorsiflex at least 65 degrees.

Leg length discrepancy

Leg length discrepancy can be as a result of an asymmetrical pelvic, tibia, or femur length or for other reasons such as scoliosis or contractures. The gait pattern will present as a pelvic dip to the shortened side during the stance phase with possible ‘toe walking’ on that limb. The opposite leg is likely to increase its knee and hip flexion to reduce its length.

Antalgic Gait

• Antalgic gait due to knee pain presents with decreased weight bearing on the affected side. The knee remains in flexion and possible toe weight-bearing occurs during stance phase
• Antalgic gait due to ankle pain may present with a reduced stride length and decreased weight bearing on the affected limb. If the problem is pain in the forefoot then toe-off will be avoided and heel weight-bearing used. If the pain is more in the heel, toe weight-bearing is more likely. General ankle pain may result in weight-bearing on the lateral border.
• Antalgic gait due to hip pain results in a reduced stance phase on that side. The trunk is propelled quickly forwards with the opposite shoulder lifted in an attempt to even the weight distribution over the limb and reduce weight-bearing. Swing phase is also reduced. 

Gait Descriptions

Note: This is not an exhaustive list.

• Antalgic gait: A limp adopted so as to avoid pain on weight-bearing structures, characterized by a very short stance phase.
• Ataxic gait: An unsteady, uncoordinated walk, with a wide base and the feet thrown out, coming down first on the heel and then on the toes with a double tap. This gait is associated with cerebellar disturbances. It can be observed in patients with longstanding alcohol dependency. Individuals with sensory disturbances may present with a sensory ataxic gait. Presentation is a wide base of support, high steps, and slapping of feet on the floor in order to gain some sensory feedback. They may also need to rely on observation of foot placement and will often look at the floor during mobility due to a lack of proprioception.
• Equinus gait: A walk accomplished mainly by flexing the hip joint; often observed in those diagnosed with spastic cerebral palsy.
• Parkinsonian Gait: Seen in Parkinson's disease and other neurologic conditions that affect the basal ganglia. Rigidity of joints results in reduced arm swing for balance. A stooped posture and flexed knees are a common presentation. Bradykinesia causes small steps that are shuffling in presentation. There may be occurrences of freezing or short rapid bursts of steps known as ‘festination’ and turning can be difficult.
• Trendelenburg gait:Characteristic of paralysis of the gluteus medius muscle, marked by a listing of the trunk toward the affected side at each step.
• Hemiplegic gait: Involving flexion of the hip because of foot-drop and circumduction of the leg.
• Steppage gait: The gait in foot-drop in which the advancing leg is lifted high in order that the toes may clear the ground. It is due to paralysis of the anterior tibial and fibular muscles, and is seen in lesions of the lower motor neuron, such as multiple neuritis, lesions of the anterior motor horn cells, and lesions of the cauda equina.
• Stuttering gait: A walking disorder characterized by hesitancy that resembles stuttering; seen in patients with neurologic damage, for example Huntington's and chorea‐acanthocytosis.
• Tabetic gait: An ataxic gait in which the feet slap the ground; in daylight the patient can avoid some unsteadiness by watching his feet.
• Waddling gait: An exaggerated alternation of lateral trunk movements with an exaggerated elevation of the hip, suggesting the gait of a duck; characteristic of muscular dystrophy.
• Neuropathic Gait: High stepping gait to gain floor clearance often due to foot drop

Summary of Gait Deviations

Observed Gait Deviation	Likely Impairement	Compensation/Mechanical Rationale
Hip
Backward leaning of the trunk during loading phase	Weak Hip Extensors	The line of gravity of the trunk moves behind the hips thereby reducing the need for hip extension torque
Forward bending of the trunk during loading response	Weak Quadriceps	The trunk is moved forward to bring the line of gravity anterior to the axis of rotation of the knee and reducing the need for knee extensors
Lateral trunk lean towards the stance (Compensated Trendelenburg Gait)	Marked weakness of the hip abductors Hip pain	Shifting of the trunk over the unaffected lower extremity reduces the demand of the hip abductors
Hip Circumduction (semicircle movement of the hip during swing phase)	Hip flexor weakness	Semicircle movement includes the combination movement of hip flexion, hip abduction and forward rotation of the pelvis
Knee
Flexed position of the knee during stance despite normal range of motion at the knee joint	Impairement at the ankle or the hip joint (Compensation occurring at the knee joint)	Exaggerated hip flexion or ankle dorsiflexion during stance results in flexion of the knee
Excessive knee flexion during swing phase	Reduced ankle dorsiflexion of the swing limb	Increase toe clearance of the swing limb. (This is accompanied with increased hip flexion)
Knee is kept in extension during loading phase (No extension thrust is observed)	Weak quadriceps	Anterior trunk lean is observed during early stance, thereby moving the line of gravity of the trunk slightly anterior to the axis of rotation
Reduced knee flexion during swing phase	Knee extension contracture	Hip hiking or hip circumduction will be observed as compensation
Ankle
Foot slap Quick ankle plantar flexion occurring after heel contact	Weakness in ankle dorsiflexors	None/less active dorsiflexion occurs during swing phase Normal dorsiflexion can occur during stance phase (if there is normal range of motion at the ankle joint)
Drop Foot Ankle remains in plantar flexion during swing phase	Weakness in ankle dorsiflexors	To prevent toes from dragging during the swing phase hip circumduction, hip hiking or exaggerated hip and knee flexion will be noted

Below are some visual examples of gait disturbances:

Age-Related Gait Changes

With age comes an increase in prevalence of gait disorders. These need investigation to reduce the burden of falls - an important consideration in the geriatric population.

Gait changes are to some degree a consequence of normal ageing, however, individual walking speed in elderly subjects is a strong indicator of general health and survival

Common gait changes seen in aging adults include:

• Increased use of protective strategies, including increasing the base of support and decreased step length, cadence and velocity.
• Increase body sway: As muscle power diminishes and proprioception and vision diminishes. In younger persons this sway can be compensated by activating the muscle groups around the upper ankle joints. Older persons shift this compensation to the proximal muscle groups around the hips due to loss of distal proprioception. This in turn, requires an increased reliance on vestibular afferent nerves, which undergo less change during the ageing process.

Clinical Bottom Line

Good knowledge of anatomy and biomechanics is important to understand the different phases of the gait cycle. When you know the normal pattern, you can see what’s going wrong!