DEFINITION OF GAIT (HUMAN)-
Gait is nothing but a person’s manner of running, walking or stepping. Gait in humans relates to locomotion gained through the movement of human limbs. Gait is a two-legged, biphasic forward driving force of center of gravity of the human body. There are different sinuous movements of different segments of the human body with minimum usage of energy. The difference in gait patterns is described on the basis of differences in movement of limb patterns, forces, overall velocity, kinetic and potential energy cycles, and variations in the contact with the ground. Human gaits can move either naturally or as a result of specialized training in different ways.
THE GAIT CYCLE-
The gait cycle includes steps and strides, is a repetitive pattern. Also, a step includes a single step but a stride involves a whole gait cycle. The step timing can be derived from one foot hitting the ground to the other foot hitting the ground. Also, the run cycle is different from the gait
There are two main phases of the gait cycle: the stance phase and the swing phase. The gait cycle includes 60% as stance phase and 40% as swing phase. The stance phase begins with the heel strike and ends at the phase between the toe off phase and the heel strike phase. With the end of the stance phase, the swing phase begins. Gait also includes the combination of open- and closed-chain activities.
Types of Gait Cycle:-
Can be classified in the following eight phases:-
- HEEL STRIKE:- Heel strike is a small duration which starts the moment the foot touches the floor. It is the first phase of double support. This phase is also known as initial contact. Here there will be 30° hip flexion and the ankle moves from 5° into plantar flexion position. Also, the knee flexion begins at 5° and goes on.
- FOOT FLAT:- During Foot flat, the body soaks the impact of the foot by rolling in pronation. It is also known as loading response phase. The knee flexes up to 15° to 20° of flexion. Ankle plantar flexion increases up to 10° to 15°.
- MIDSTANCE:– During the midstance phase, one single leg supports the body. Here, the body starts moving due to force absorption at impact to force propulsion forward. Here, the hip moves from 10° of flexion to extension. Also, the ankle becomes supinated and dorsiflexed. The knee reaches to the maximal flexion and begins to extend.
- HEEL OFF:- When the heel leaves the floor, heel off phase begins. Here, the body weight. There will be 10° to 13° of hip hyperextension, which later flexes. The knee becomes (flexed) 0° to 5° and the ankle supinates and plantarflexes.
- TOE OFF:- In this stage, the hip becomes less extended and the knee flexes up to 35° to 40°. Also, the plantar flexion of the ankle increases up to 20°. As the name mentions itself, that in this stage the toes leave the ground. This phase is also known as the pre-swing phase.
- EARLY SWING:- In the early swing phase, the hip extends to 10° and later flexes due to contraction and the knee flexion increases up to 40° to 60°. Also, the ankle goes from 20° of plantar flexion to dorsiflexion, to end in a neutral position.
- MID SWING:- In the midswing stage, the hip flexes up to 30° by contraction. Also, the ankle becomes dorsiflexed. Also, the knee flexes 60° but later extends approximately 30° due to contraction.
- LATE SWING:- The late swing phase is also known as declaration phase. This phase begins with flexion in the hip up to 25° to 30°. Also, there will be a locked extension of the knee and a neutral ankle position.
Pathological gait is a modified gait pattern because of weakness, deformities or other impairments. These modifications can be derived into neurological or musculoskeletal causes.
- MUSCULOSKELETAL CAUSES-
Pathological gait patterns happen as a consequence of musculoskeletal may happen cause of imbalanced soft tissue, bony abnormalities or joint alignment. These often inflict on one joint then impacts on other joints, as a result, it affects the gait pattern. The common deviation can be explained in detail below.
- HIP PATHOLOGY:-
- Arthritis– A very common cause of pathological gait is arthritis. During swing phase, the range of movement of an arthritic hip has reduced, due to which an exaggeration of movement causes in the opposite limb ‘hip hiking’.
- Excessive Hip Flexion– Due to IT band contractures, Hip flexor spasticity, Hip flexion contractures, hip pain, Compensation for excessive knee flexion and ankle DF, Compensation for excess ankle plantar flexion in mid-swing, most commonly the excessive hip flexion can significantly change the gait pattern.
- Hip Abductor Weakness– During the swing phase to allow the opposite leg to lift, the abductor’s muscles stabilize the pelvis.
- Hip Adductor Contracture– Due to weak adductor muscles, the leg crosses midline during swing phase, this can be said as ‘Scissor Gait’.
- Weak Hip Extensors– To lessen the hip flexion required from initial contact, weak hip extensors will cause a person to take a smaller step. As a result, lesser force of contraction required from the extensors.
- Hip Flexor Weakness– The weakness hip flexor results in a smaller step length due to the weakness of the muscle to create forward motion.
- KNEE PATHOLOGIES:-
- Weak Quadriceps– During flexion through stance phase, quadriceps eccentrically control the knee.
- Severe Quadriceps Weakness– During the initial contact to stance phase, instability at the knee joint will present in hyperextension. As the body weight moves forwards over the limb, the knee joint will ‘snap’ back into hyperextension.
- Knee Flexion Contraction– The limping type of gait pattern exists cause of knee flexion contraction. The heel strike is limited and step length is reduced as the knee is restricted in extension. During the stance phase, the person is likely to walk on the toe to compensate.
- ANKLE PATHOLOGIES:-
- Ankle Dorsiflexion Weakness– The lack of heel strike and decreased floor clearance can be result cause of ankle dorsiflexion weakness. As a result, there will be the increase in step height and swing phase will be prolonged.
- Calf Tightening or Contractures– Due to a period of trauma there will be calf contractures which will cause the reduction in heel strike cause of restricted dorsiflexion. As a result, the person is likely to ‘toe walking’ during stance phase, also to ensure floor clearance the step length will reduce and excessive flexion of the knee and hip flexion during swing phase.
- LEG LENGTH DISCREPANCY:- Due to an asymmetrical pelvic, femur length or tibia or cause of another reason like scoliosis or contractures there can be leg length discrepancy. During the stance phase, the gait pattern will present as a pelvic dip to the shortened side with possible ‘toe walking’ on that limb. To reduce its length the opposite leg is likely increased its knee and hip flexion.
- ANTALGIC GAIT:-
Due to knee pain, the antalgic gait presents with decreased weight bearing on the affected side. During stance phase, there will knee flexion and possibility of weight bearing on the toe.
Due to ankle pain, the antalgic pain presents with a reduced stride length and decreased weight bearing on the affected limb. The toe off will be avoided and height bearing used if there is the pain in the forefoot.
reduced stance phase on that side. To even weight distribution over the limb and reduce weight bearing, the trunk is propelled quickly forwards with the opposite shoulder lifted. Also, there is the reduction in swing phase.
COMMON NEUROLOGICAL CAUSES OF PATHOLOGICAL GAIT–
- HEMIPLEGIC GAIT:- The Hemiplegic Gait can happen due to a stroke. The upper limb flexion is adducted and internally rotated at the shoulder. Also, the lower limb is in rotated position internally, the knee is extended and the ankle is inverted and planter is in flexion position.
- DIPLEGIC GAIT:- The spasticity is generally associated with both lower limbs. A ‘scissor’ type of gait with the narrowed base of support can be created by contractures of the adductor muscles. One can result in plantar flexed ankles presenting in ‘tip-toe’ walking toe and often toe dragging due to spasticity in the lower half of the leg. To overcome this excessive hip and knee flexion required.
- PARKINSONIAN GAIT:- The parkinsonian gait can occur during Parkinson’s disease or also associated with conditions which cause parkinsonisms. The arm swing for balance reduced due to the rigidity of joints. The common presentation is stopped posture and flexed knees. The freezing or short rapid bursts of steps can happen, known as ‘festination’ and turning can be difficult.
- ATAXIC GAIT:- Ataxic gait is an uncoordinated step with a wide base of support and variable foot placement. It is associated with cerebellar disturbances and it can be observed among the patients having longstanding alcohol dependency.
A sensory ataxic gait can be observed among the people with sensory disturbances. There is a presentation wide base of support, high steps, and slapping of feet on the floor in order to gain some sensory feedback. Due to lack of proprioception, they also need to depend on observation of foot placement and may look at the floor during mobility.
- MYOPATHIC GAIT:- If the hip muscular dystrophy is bilateral the presentation will be a ‘waddling gait’ and if it is unilateral it will be presented as a ‘Trendelenburg Gait’.
- NEUROPATHIC GAIT: Due to foot drop, high stepping gait to gain floor clearance often due to foot drop.
To gain information in the biomechanical mobility examination about foot dysfunction in dynamic movement and loading, the analysis of the gait cycle plays a vital role. It will be good to examine one joint at a time while analyzing the gait cycle. There are two methods which can be used are Objective and subjective methods. An objective approach is based on quantitative and parameters like time, muscle activity and distance measurement. Some of the objective methods to examine the gait cycle are as follows:-
- Electronic and Computerized Apparatus
- Electronic Pedometers
- Video Analysis and Treadmill
- Satellite Positioning System
The quantitative methods to assess and analyze the gait cycle are given below:-
- Ten Meter Walking Test
- 6 Minute Walking Test
- 2 Minute Walking Test
- Dynamic Gait Index
- Emory Functional Ambulation Profile
- Timed Up and Go Test
- Functional Ambulation Categories