Spasticity is a tense reflex activity, caused by a state of disinhibition, which often occurs in a fixed pattern and thus constitutes a specific profile for patients with hemiplegia.
Specific manifestations.
Head: flexion to the affected side, face turned to the healthy side.
Upper limbs (flexion pattern)
Scapular girdle: posterior withdrawal, sinking.
Shoulder joint: internal retraction, internal rotation.
Elbow joint: flexion.
Forearm: rotate anteriorly.
Wrist joint: palmar flexion, ulnar deviation.
Fingers; flexion, internal retraction.
Trunk: flexion to the affected side and rotation to the posterior.
Pelvis: elevation to the affected side and rotation to the posterior.
Lower extremity (extensor pattern)
Hip: extension, inversion, internal rotation.
Knee: extension.
Ankle: plantarflexion, internal rotation.
Toe: flexion, pronation.
Spasticity is not stereotypically irreversible, but develops through interaction with the environment as a result of reinforcement of abnormal activity.
Bobath used the following six points to compose the basic training for spasticity control.
(1) Application of antispastic limb positions.
(2) Weight-bearing on the affected side.
(3) trunk rotation.
(4) extension of the affected upper extremity.
(5) forward extension of the shoulder.
(6) Correct training protocol.
Joint response
An abnormal change in the movement of a part of the body that is not related to the movement or a greater range of the body or a posture that is fixed when a part of the body is moved due to random exertion or stimulation of reflexes.
Joint reactions have the following adverse effects on patients with hemiplegia.
(1) The joint response causes increased spasticity in the upper and lower extremities of the patient, and the limbs are forced into fixed limb positions that make it difficult to perform the functionally required movements. For example, plantar flexion and inversion of the ankle joint and extension of the lower limb when putting on shoes result in inability to complete the movement of putting on shoes. Patients who make an effort to do so will further intensify the extensor spasm.
(2) If the upper extremity is frequently in the flexed position, this can lead to joint contractures (especially in the elbow and fingers) and affect the improvement of upper extremity function.
(3) The joint response affects the balance response of the upper and lower extremities, resulting in a generalized balance dysfunction.
(4) Aggravating contracture and affecting improvement of motor function.
Compensatory movements
Substitution is the counteracting of the abnormal state of the deficit by another part of the larger activity.
Functional goals are achieved by using the casual movements of the healthy side.
The development of compensatory movements has the following effects on motor function in patients with hemiplegia.
(1) Asymmetry of movement.
(2) Transfer of weight to the healthy side.
(3) Reduced ability to shift the center of gravity. (Insufficient transfer of body weight to the affected side during walking, resulting in a significant shortening of the support phase on the affected side and abnormal gait)
(4) Reduced stability. (The movement is completed by the healthy side only)
(5) Abnormal sensation of shifting the midline of the body to the healthy side.
(6) The balance response is suppressed.
(7) Further decrease in motor function.
Limb association movement
Limb association movements are pathologically abnormal movement patterns. Examples of the effects of upper extremity joint band movements on the motor function of patients are as follows.
(1) Due to the effect of upper limb flexor joint band movement, shoulder joint flexion is accompanied by abduction and external rotation, so there is difficulty in touching the head with the hand, resulting in the inability to complete all movements that need to be accompanied by internal retraction and internal rotation such as combing the hair, washing the face and brushing the teeth when the upper limb is raised.
(2) Since the flexion of the shoulder joint is accompanied by the flexion of the elbow joint and the rotation of the forearm, the elbow joint cannot be extended when the upper limb is extended forward, and the movement of picking up objects in all directions cannot be completed.
(3) The flexor band movement of the upper limb causes palmar flexion of the wrist joint and finger flexion, so the function of picking up objects is lost.
(4) When the upper extremity is extended, the elbow joint cannot be flexed due to the linkage movement of the extensor muscles, so the patient loses all daily life movements that require shoulder extension and elbow flexion, such as putting on pants, bathing, going to the toilet, and touching the back.
Lower limb joint movement
The effects of lower extremity joint band movement on the patient’s motor function are as follows.
(1) Due to the influence of the lower limb flexor band movement, hip flexion is accompanied by abduction and external rotation, so when the patient lifts the leg, the lower limb must be tilted outward, which affects the gait.
(2) Due to the influence of the lower limb extensor band movement, the knee joint cannot complete flexion when the hip joint is extended, and the ankle joint appears plantar flexion and inversion, so the patient feels difficulty in stepping and has to tilt the pelvis to the healthy side and draw the lower limb on the affected side in a circle, resulting in an abnormal gait.
(3) Since the hip joint extends and the ankle joint appears plantarflexed and inwardly turned when standing, the patient cannot achieve full foot landing, which affects the balance and stability of the body.
Tension labyrinth reflex (4 months)
Tension labyrinth reflex is caused by the change of the patient’s head position in space and is a reflex at the level of the brainstem.
Clinical features.
Supine position: increased extensor tone, spinal extension, head tilted back, shoulder joint retraction, and extension of the extremities.
Prone position: increased flexor tone or reduced extensor spasm
Patients with hemiplegia are often affected by the tonic labyrinth reflex, which manifests as follows.
(1) If the wheelchair is used for a long time, the trunk is flexed and the head has to be raised and the neck extended when looking around, resulting in increased extensor tone in the lower extremities, hip extension, hip sliding forward, knee extension, and foot slipping off the tread, causing the patient to be in a semi-recumbent position with left and right asymmetry.
(2) When performing turning movements, the neck extension leads to increased tension of the extensor muscles, and one lower limb cannot complete the forward leaning movement, making it difficult to complete turning.
(3) When standing, the patient’s head is extended backward, the tension of the extensor muscles of the lower extremity is increased, the shoulder and trunk are extended backward, and the knee joint is hyperextended and cannot be flexed, which, together with the plantar flexion and inversion of the ankle joint, causes an abnormal movement pattern.
(4) When walking, also due to the effect of extensor tone, flexion of the lower extremity is difficult and the patient has difficulty in taking forward steps.
Symmetrical tension neck reflex (6 months)
The following characteristics of the patient’s posture and movements appear.
(1) When lying in bed in a semi-recumbent position with the pillow under the head and trunk too high, or when riding in a wheelchair with the neck and trunk in a flexed position, the tension of the lower extremity extensors and upper extremity flexors on the affected side is increased.
(2) When the patient sits up from the supine position, the movement is difficult to complete because of the increased tension of the extensor muscles of the lower extremity due to the head lifting movement.
(3) When walking, the patient looks down at the ground, causing increased tension in the extensor muscles of the lower extremity. In the support phase on the affected side, the knee joint appears hyperextended, the ankle joint is plantarflexed in contact with the ground, and in the swing phase, the hip and knee joints cannot be fully flexed. The upper extremity is in flexion and the joint response is again reinforced by the position of the head.
(4) When the patient is transferred from bed to wheelchair, due to head lifting, the upper limb is extended to support the bed, resulting in increased flexor tone of the lower limb on the affected side, knee flexion, and inability to land on the foot, making the affected side unable to bear weight.
(5) When walking, the head is raised and the neck is extended, resulting in increased flexor tone in the lower extremity, and the affected extremity cannot bear weight.
Asymmetrical tension neck reflex (6 months)
The following effects on the patient’s posture and movements occur.
(1) When the patient extends the upper limb, he or she turns the face to the affected side with force. If the face is not turned to the affected side, the elbow joint cannot be extended.
(2) In patients with upper extremity flexor spasm, the elbow joint is often in a flexed position, but when the face is turned to the affected side, the elbow joint is unable to complete the flexion movement. When eating, washing face, combing hair and other daily life actions, the upper limb on the affected side is flexed and the face must be turned to the healthy side, which affects the completion of normal life actions. The face must be turned to the healthy side, which affects the completion of normal life movements.
(3) Patients with hypotonia of the lower extremities often stand with their faces facing the affected side with assistance, so that the extension of the lower extremities is reinforced. This posture interferes with the normal balance response and should be suppressed.
Positive support reflex (3-8 months)
The positive support reflex is when the end of the toe and the skin of the inner bunion and little toe are stimulated, causing the interosseous muscles to stretch and stimulate the proprioceptors, resulting in increased tension in the extensor muscles of the lower limb.
The following effects on the motor function of the affected limb occur.
(1) Hyperextension of the knee joint of the affected limb, plantar flexion and inversion of the ankle joint, affecting the foot following the ground in the support phase.
(2) When the affected side is in the support phase, the ankle joint is plantarflexed, making it difficult to complete the weight transfer movement.
(3) When training the ankle dorsiflexion movement of the affected limb, try to prevent stimulation of the toes resulting in increased flexor tone.
Crossed extension reflex (2 months)
Clinical manifestations.
(1) When the patient does the hitching motion in bed, if the lower limb on the healthy side is lifted, the lower limb on the affected side will fall down under the influence of crossed extension.
(2) Patients use one leg weight-bearing of the healthy lower extremity, and, when rising from a sitting position, the affected lower extremity will be flexed as long as the healthy lower extremity is actively extended, and this reaction will affect the weight-bearing of the affected extremity.
(3) In some patients, the affected lower limb can stand on one leg, and the knee joint can complete the flexion action when weight-bearing, and there is no excessive tension of the extensor muscles; however, when the lower limb on the healthy side steps forward and is in flexion, the affected lower limb will have an extensor hyperactivity pattern, causing a balance disorder, and when the affected limb enters the swing phase, it will have difficulty in flexion and affect walking.
Grasping reflex
Manifestations.
(1) Whatever object is placed in the patient’s hand causes increased flexor tone in the elbow, bowl joints and fingers.
(2) In patients with severe finger flexion spasms, therapists have in the past designed orthoses for the patient, or fixed the fingers in the extended position by placing objects such as towel rolls in the hand for the patient to grasp. This method often led to an increase in spasticity because it stimulated the grip reflex.
(3) In the past, therapists designed grasping tennis balls or rubber rings with stimuli in order to allow patients to practice hand grasping, etc. This activity often affects the hand extension function by eliciting the grasping reflex.
(4) During training, in order to use the self-assisted method, the fingers of both hands are crossed. As the fingers of the healthy side reach from the proximal to the distal end of the affected palm, the gripping reflex is elicited, resulting in the flexion and inversion of the fingers, making it difficult to complete the movement.
(5) Although some patients have mastered the motor function of random finger extension, they often encounter difficulties when they have to release the object in their hands due to the influence of the grasping reflex.
Balance disorder (balance response – cerebrocortical level)
Manifestations.
(1) In those with normal sitting balance response, when the body’s center of gravity changes, there will be contralateral adjustment of the head and chest toward the center of gravity, as well as extension and abduction of the upper and lower extremities to maintain the sitting posture; if the patient’s sitting balance disappears, he or she will not be able to maintain the sitting posture independently.
(2) In those with normal balance response in standing position, if external force causes disruption of balance when standing, various adjustment responses of the head, trunk and ankle joints appear at any time. If balance is still not maintained, a stride response in the corresponding direction will appear to maintain body balance. However, patients with standing balance disorder cannot stand and walk independently even if their lower limbs function well.
(3) Due to the poor balance function, patients have the fear that they may fall at any time, which makes the whole body muscles highly tense and aggravates the spasm of trunk and extremities.
(4) A few patients ignore the importance of balance function and lack of protection awareness, leading to trauma, which often results in serious injuries such as fractures due to inadequate adjustment and protective responses.
Sensory impairment
Examples of the effects on hemiplegic patients are as follows.
(1) Due to the loss of sensation, the patient lacks motor awareness and cannot correctly judge whether the lower limbs are on the ground or not, which makes the patient lack confidence in the balance and stability of walking and creates a sense of fear.
(2) Loss of joint sensation leads to impairment of joint position and motion recognition. The patient closes his eyes and checks the angle of flexion and extension or flexion and extension of his joints, but the patient cannot accurately judge, so it is difficult to control the height of leg lifting, resulting in abnormal gait.
(3) When holding objects in the affected hand, the patient cannot judge the shape and temperature of the object, which also affects the self-care of daily life.