Introductory Chapter: Introduction to Rehabilitation

1. Introduction

Rehabilitation robotics is part of an approximately new and constantly growing field, especially in the clinical environment. Pioneering technologies have been discovered since the late 1980s and early 1990s, with the recovery induced by sensory-motor function training applied to animals with central nervous system (CNS) damage [1].

The use of machines in rehabilitation, however, comes much earlier, through a patent proposed in 1910 by Theodor Büdingen, which develops an electrically operated machine in order to guide and support walking movements for patients with heart problems.

In 1930, Richard Scherb developed the first man-operated, cable-operated mechanotherapy machine to mobilize joints, followed by the development of the first robotic rehabilitation system based on continuous passive movement, which was dependent on the patient’s contribution due to its rigid connection system.

The applicability of robots in the therapeutic field has been introduced since the 1970s with the advent of the first monitored exoskeletons and equipped with pneumatic, hydraulic, or electromagnetic batteries for position control. These included advanced features such as ankle flexion/extension, adduction/abduction of the hip required for increased stability, and exoskeleton movement that could be carefully controlled by the therapist through the movement of one’s own body (similarly connected exoskeleton) [2]. Thus, the first system invented for robot-assisted therapy for post-stroke patients was based on a rigid industrial maneuver, which did not allow interaction with patients, but only moved a tampon in different areas for patients who had to touch it.

In 1989, with the advent of MIT-MANUS equipment, first tested in 1994, a new era of neurorehabilitation robotics took place. This plantar manipulator had a low impedance (resistance detected during movement between the human-user interface and the robotic system) so that it provided increased stability of the upper limb by unloading it against the weight, being excellent for the severity of deficits [3, 4].

After a few years, the new generation of force-controlled devices used in bimanual gripping and lifting movement is also introduced, which led to the initiation of a more advanced control interaction, for the passive movements of patients with severe disabilities and for the assisted active movements of patients with moderate disabilities.

At the same time, mirror image motion enabler (MIME) appears on the market, which is equipped with a rigid industrial robot and offers support in performing paralyzed limb movements, but through the movement diffuser, it controls the healthy limb (mirror image therapy) [5].

For the extremity of the lower limb, rehabilitation robots have been developed since 1994, when the Locomat neurological recovery equipment was launched, which supported the body weight with the help of a robotic walking orthosis, simultaneously with its training on the treadmill, as well as the appearance of the GIT Trainer equipment with a similar concept, but with a final effect design [6].

Lokomat is an exoskeleton-type system, essential in the process of relearning independent walking, which involves activating the balance by lateral movements and rotation of the pelvis, with the help of a support platform of the center of gravity.

During therapy, attractive exercises are performed, which stimulate the patient’s effort and motivation by including competitive elements and a data storage system. All aspects of gait recovery are monitored, such as the path of the foot during the gait cycle (initial contact and detachment) and the length of the step, so that the option to increase the level of movement is beneficial in the relearning process [7, 8].

The following years after these discoveries, a wide range of rehabilitation robots for the lower and upper limbs were brought, being classified globally according to their complexity as follows: stationary exoskeletons, on the ground; effector skeletons with remote operation through a device called Gripper; portable exoskeletons.

The first two categories of exoskeletons are well defined, compared with the portable exoskeletons that are currently undergoing clinical testing.

Therefore, rehabilitation robots must allow a physiological stimulation of the limbs in performing training with the functional movements of the affected segments, but also on the stimulation of peripheral receptors for functional training in performing the step.

With this historical and clinical background of real importance in the field of rehabilitation robotics, the neurophysiological basis is underlined in the design of recovery equipment that will follow in the future developments [9, 10].

Currently, there is interesting equipment on the market in the field of rehabilitation robotics, ranging from hard, fixed structures to light structures that are customized and directly operated. The combination of robotics with non-invasive and invasive brain-machine interfaces or neuro-prostheses in order to determine independence in everyday life is also at an early stage [11, 12].

Bionic technologies make possible the human connection with the interface of computer systems. They are called brain-computer interfaces (ICCs) also known as BCIs. These interfaces are either input, when they generate signals related to the nervous system or output, when the signal triggered by the wearer’s nervous system was recorded and processed by the ICC, in order to control a computer or a robotic system.

The development of the first exit ICCs is aimed at recovering motor and communication skills in patients with spinal tract disorders and muscular dystrophies with disabilities, but also having amyotrophic lateral sclerosis. The interfaces connect to robotic manipulators and robotic wheelchairs, and also to programs that allow the recording of clamping actions and movement all based on the analysis of thinking activities.

Fundamental in the design of the output ICC, the first systems used the type of nerve signal based mainly on electrical signal. The electrodes used to detect electrical signals can be placed on the scalp in the case of Electro Encephalo Graphy—EEG, on the area of the cerebral cortex or deep in the brain tissue. In this way, the concept of an ICC is the basis for detecting electrical peaks in the brain, digitizing them and translating those actions that the brain does, thus providing control over the devices around us, with just one thought [13, 14, 15].

The three main categories of ICC are invasive—those implanted in the brain and provide a good reception in the ability to gather essential information about neurons and their activity; partially invasive (Neuralink)—placed in the skull, but not directly on the brain, which are safer, more effective, and less intense surgically; non-invasive—in the form of rubber hats and helmets with electrodes. They are easy to use, but because they are located away from the brain, electrical signals are not as accurate as brain implants.

Since 1969, scientists have successfully completed the project in which monkeys moved a needle on the dial of a computer, using only brain signals. In 2008, the brain was used to control the arms of a food-producing robot. The monkeys move the robot’s arms after receiving feedback to the area responsible for controlling the arms, like a real arm.

In 2006, a study was conducted that allowed a robotic limb to be manipulated using the brain computer interface (BCI) with electrodes inserted into the user’s motor cortex, a program that tracked human interaction with household appliances [16].

Following the fact that in 2014 people successfully used brain signals to control robotic arms and legs, the proof is shown by Juliano Pinto, the paraplegic who used a mind-controlled exoskeleton at the World Cup in Brazil.

Neuralink is part of a partially invasive ICC project and uses robotic tools to implant tiny wires into the brain. At present, it is still necessary to make small holes in the scalp, but in the future, they will be made with a laser.

The wires implanted in the form of chips are connected to an external device, called the link, which translates the signals provided by the brain and sends them to other devices. Currently, studies are being done on animals and will be performed on people, especially those with medical needs, but also for the use of other devices such as smartphones.

Cyberkinetics developed in 2004, the first modern BCI, a brain implant called Brain Gate, through which carriers were able to connect their brains to the computer, and in 2012, the company demonstrated the effectiveness of the device by controlling a robot arm by the brain. People with spinal nerve injuries enjoy limb control by using these brain signals [17].

Thus, the development of non-invasive ICC applications on EEG targets a wide range of potential users. The current projects of companies interested in the study of BCI technologies are limited to non-invasive devices, such as: emotional electroencephalograph headphones that take the signals from the brain, analyze them, and provide the consumer with information about how to use the devices; Neurable—a non-invasive BCI, hands-free, voiceless headset with VR technology to train the mind in virtual limb adaptation.

In the area of prostheses and neuro-prostheses, the research was performed on invasive solutions of brain computer interfaces, thus aiming to intercept muscle activity by means of electrodes placed on the user’s skin (electromyography).

Such prosthesis is represented by the robotic hand Michelangelo, produced by the German company Otto Bock HealthCare, through which the subjects controlled the movements of the robot limb with the help of the activity of their own muscles. This is the first electronically operated device that mimics the natural movements of the human hand and is used for a variety of everyday tasks (cooking, ironing, brushing, driving). The material of the prosthesis is anthropomorphic elastic adaptable for each user, and the built-in electrodes detect the movements of the healthy muscles of the wearer, which are interpreted at the software level by electromyography.

Since 2008, Advanced Arm Dynamics has used prostheses on both civilians and military amputators in the United States and the United Kingdom, and will be deeply involved in their development and testing in the coming years [18]. This research is still in full swing, and technology is evolving from functional recovery devices to care devices, assisting to make up for existing sensory-motor impairment.

Subsequent advanced approaches for actuation, detection, and control make simple devices robust with clinical and home applicability.

In the future, wearable devices require the ability to adapt, but also to reduce the support of recovery plates, thus compensating for chronic deficiencies.

Developed robotic control technologies to assist people with disabilities have provided additional support by manipulating objects with the help of robotic arms, installed on desks or benches for the purpose of handing over objects.

Physical interaction systems with other devices, such as PAM-Aid (Personal Adaptive Mobility) and NavChair (developed by the University of Michigan), have also been developed since 2001.

NavChair has a wheelchair, equipped with a mechanism to control movement, and avoids obstacles, determined by the activity of detection and control of position sensors. Such a support can be provided while driving and robots such as PAM-Aid, which have the ability to avoid obstacles, but also to brake independently in the event of unforeseen obstacles.

Therefore, future approaches offer a number of challenges for both therapy and robotic care, many requiring a deep understanding of the neurophysiological systems underlying sensorimotor functions, as well as collaboration with industry and non-governmental organizations.

Also, in the future, the design of exoskeletons will involve much more work, with better materials and with easy design and control, and with the improvement of nanotechnology, we will move toward an era in which cyborgs will become a necessary reality [2].

Thus, the study and future research are related to the biomechanics of the spine, the morphology of the locomotor system, gait; however, neuronal control remains extremely important.

2. Anatomy of the spine and nervous system, diseases, and methods of recovery

The study of human anatomy has had a long history, dating back to antiquity, through the embalming of corpses, which led to the first descriptions of the brain and its membranes and later in the Renaissance, known as the period of anatomy today.

During the two great periods, the study of the human skeleton led to the discovery of the 200–220 bones, of which it is composed of the following main structures: spine constructed of 33–34 vertebrae (7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal); chest with 12 pairs of ribs; skull (29 bones); upper limb bones (64 bones); bones of the lower limbs (62 bones).

These structures that make up the human skeleton are directed, from a functional point of view, through a complex system of the organism called the nervous system, which offers the possibility for the whole organism to communicate with the environment.

In turn, any damage to the existing structures of the human skeleton causes the development of diseases of the spine with the need to apply locomotor or neuromotor rehabilitation treatments.

In developing countries, spinal cord injuries are one of the leading causes of death in the first 40 years of life and are also responsible for increasing the number of disabilities due to associated trauma (pelvic fractures 18%, long bone fractures 14%, craniocerebral fractures, thoraco-abdominal injuries) [18].

The main cause of acquired disability worldwide remains the field of neurological disorders (strokes, craniocerebral trauma, and neurodegenerative diseases), which requires methods and techniques of recovery in the field of neurorehabilitation.

Following the synthesis provided by Reinberg, the spine is an extremely important segment from a functional point of view, consisting of 33–34 bones, 344 joint surfaces, 24 intervertebral discs, 365 ligaments, and 730 dotted areas of insertions and origins of muscle bundles. The spine is divided into four regions consisting of a fixed number of vertebrae: the cervical region (neck) consisting of seven cervical vertebrae with a role in ensuring the mobility of the head. This function is provided by the morphological peculiarity of the cervical vertebrae with a larger transverse diameter of the vertebral bodies. The thoracic region (thorax) consists of 12 thoracic vertebrae. The position and oscillation of the center of gravity is represented by the particularity of the vertebrae in this area, through which diameter is larger in the anterior-posterior area. The lumbar region, with five vertebrae and large diameter in the transverse area of the vertebral bodies, offers increased mobility. The sacral region (pelvis) with five sacrococcygeal vertebrae and welded is called false vertebrae. The coccygeal region is represented by an axillary-like triangle, with the tip down and formed by the union of 4–5 vertebrae.

The vertebral column shows the articulation in the upper floor of the cervical vertebrae with the skull, and in the lower floor, it articulates through the sacrum with the coxal bones [19].

The spine occupies an important place in human physiology, being the central axis of the human body that fulfills the mechanical aspects: rigidity and elasticity.

Overall, it consists of three normal curves presented as follows: cervical curvature with anterior convexity; dorsal curvature with posterior convexity; lumbar curvature with anterior convexity; sacral curvature with posterior convexity.

The presence of these physiological curves gives the spine an increased resistance of up to 10 times higher for heavy loads.

The movements of the spine are varied and complex as a result of the cumulative movement of all the connecting elements: intervertebral diarthrosis, intervertebral discs, intervertebral symphysis, including the movements of the intervertebral joints (flexion, extension, lateral tilt rotation).

From the point of view of the articulation of the vertebrae, this is done through a symphysis with the interposition of the fibrocartilaginous disc, called the intervertebral disc, which in turn consists of a nucleus pulposus with a content of 90% water and fibrous ring.

In the back area, the upper and lower vertebrae articulate with each other through simple arthrodesis thus making the sliding motion possible.

The main joints that make possible the varied movement of the spine are as follows: (i) The costovertebral joints with an important role in respiratory biomechanics ensure the union between the vertebral extremities of the ribs with the spine; (ii) the joints of the rib head are flat diarthrosis that connect the joint face of the rib head and the body of two adjacent vertebrae; (iii) the costotransversal joints are diarthrosis that connect the articular face of the costal tubercles for the first 10 ribs and the costal face on the transverse apophyses of the first 10 thoracic vertebrae; (iv) the sternocostal joints formed at the union of the cartilages of the 2–7 ribs with the costal incisions of the sternum.

The stability of the spine is provided by the presence of the posterior longitudinal ligament placed posteriorly by the vertebral bodies, the anterior longitudinal ligament placed anteriorly by the vertebral bodies, as well as the presence of the spinal muscles, located in two superficial and deep layers. The most protected area from a muscular point of view is the portion of the lumbar area.

Due to these multisegmental structures, the spine performs a complexity of static and dynamic functions, such as: (i) static function—resistance in the application of the force of gravity and in the support of the head in position; (ii) dynamic function—complexity in performing active and passive movements; (iii) neuroprotective function—overlapping vertebrae and forming the spinal canal in which the spinal cord is located.

From the point of view of the function performed, the nervous system is present, as one of the most complex functional systems of the human body, without which it is not allowed to communicate with the external environment.

The anatomical division of the nervous system involves its division into several aspects: (i) the central nervous system consisting of the spinal cord located in the spinal canal and in the brain in the cranial box. The encephalus consists of the brainstem (bulb, bridge, midbrain) cerebellum, diencephalon (thalamus, metatalamus, epitalamus, hypothalamus, and subthalamus) and telencephalon, and (ii) peripheral nervous system represented by spinal nerves and cranial nerves.

From a functional point of view, the nervous system is divided as follows: (i) somatic nervous system, with direct communication with the external environment; and (ii) vegetative nervous system, with direct communication with the internal environment and in turn divided into central nervous system and peripheral nervous system [20].

From a structural point of view, the nervous system is structured from (a) gray matter that in turn consists of the bodies and dendrites of neurons, placed like a nucleus; (b) white substance consisting of myelinated axons arranged in cords, tracts, and bundles; (c) reticular formation and ependyma.

The nervous system consists of neurons and neuroglia with the function of supporting neurons.

The spinal cord is located in the neural canal of the spine and is an elongated portion of the central nervous system, occupying 2/3 of the upper portion of the spinal canal. Its length is 42–45 cm and extends from the upper edge of the atlas to the level of the vertebrae L1–L2, having in the upper part the spinal bulb and the lower medullary cone. The spinal cord is covered by the spinal dura mater, the spinal arachnoid, and the spinal pia mater and separated by the subdural and subarachnoid space, respectively.

Depending on the exit points of the spinal nerves, the spinal cord is divided into several parts as follows: cervical portion with cervical areas 1–8; thoracic portion with thoracic segments 1–12; lumbar portion with lumbar segments 1–5; sacral portion with sacral segments 1–5; coccygeal potion with coccygeal segments 1–3.

The spinal nerves originating in the spinal cord represent the communication of nerve flow from the external environment to the spinal cord. These pathways are formed by joining the nerve fibers of the nerve roots in the anterior and posterior area after passing through the three sheaths of the spinal cord [10].

The spinal nerves are mixed, made up of sensory, motor, and associative fibers.

The presence of the 31 pairs of symmetrical and meta-symmetrical distributed spinal nerves is as follows: 8 pairs per cervical area; 12 pairs on the thoracic area; 5 on the lumbar area; 1 on the coccygeal area.

Anastomosis of the branches of the spinal nerves causes the formation of distributed nerve plexuses and these depend on the irritated area: (a) The cervical plexus formed by welding the anterior branches of the first four cervical spinal nerves; (b) gill plexus formed by welding the anterior branches of the last four pairs of cervical spinal nerves (C5–8); (c) the intercostal nerves with 12 thoracic nerves, which form muscle and skin branches; (d) lumbar plexus formed by welding the anterior branches of the T12 and the first four lumbar nerves. It innervates the area of the abdominal wall, obturator muscles, thigh, genitals, leg, and leg; (e) duplex plexus formed by joining the anterior branches of the fourth sacral nerve and innervates the pelvic muscular and visceral area; (f) the coccygeal plexus formed by the union of the anterior branches of the fifth sacral nerve and the coccygeal nerve with the innervation of the ischia coccygeal area.

3. Displacement and range of motion achieved in the spine and musculoskeletal system (biomechanics)

The movement and range of motion achieved in the spine include all the movements of the kinematic elements of the human body through a reference system.

This reference system is the fixed or mobile benchmark against which all the positions of a system under evaluation are measured. Thus, a motion reported and compared with a fixed reference system is called an absolute motion, while the measured motion at a mobile reference system is called a relative motion.

The human body can perform simple transitional movements and rotational movements, all due to the complex and simple joints of the spine, but also of the musculoskeletal system. The rest of the body movements, the pivoting movements and the roto translational movement are achieved by completing the simple movements both in space and in plan.

In the biomechanics of the spine, the origin of the reference system is usually in the center of gravity of the human body, which moves with the human body and is called the relative or cardinal reference system.

The biomechanics of the spine have certain degrees of freedom offered by different segments: vertebrae: C3-C4-C5-C6-C7 perform the flexion movements—extension of the front, back and side of the upper limbs, being the most flexible vertebrae; the T1-T10 vertebrae are the most fixed by their articulation with the ribs and later they articulate with the sternum; the T11-T12 vertebrae are mobile because they have a joint with false, mobile ribs; the L1-l5 vertebrae are also mobile. They allow flexion extension of the lumbar area.

The sacral and coccygeal vertebrae are fixed, immobile, and welded.

In the case of spinal injuries, the emphasis is on their physiological and anatomical features, as follows: (i) The cervical vertebrae are smaller and thinner than the lumbar ones, these being the most affected in vertebral traumas; (ii) the transitional position between the mobile and the immobile area is extremely important, because the cervical vertebrae are at a point that has a kinematic energy applied in the collision as the highest; (iii) injury of the spinal cord in the cervical area will cause tetraplegia, and injury in the lumbar area paraplegia.

The movement of the joints of the locomotor system involves knowledge of the anatomical systems about his components and how human locomotion is performed. The locomotor system has a set of anatomical systems, including the osteo-articular system, the nervous system, and the muscular system.

4. Diseases and recovery of the spine

The most common spinal disorders are as follows: (i) Herniated disc is an effect of a neurological nature characterized by the sliding of the nucleus pulposus of the intervertebral disc along the spinal cord with compression of the spinal nerves and the determination of painful radiculopathy. It can be as the result of a spinal cord injury, common in the lumbar and cervical region; (ii) discopathy is a condition of the intervertebral disc with aging and deterioration of the disc with reduced flexibility and mobility; (iii) lumbosciatica is a condition manifested by pain, tingling, numbness caused by irritation of the sciatic nerve as a result of narrowing of the spinal canal (spinal stenosis), osteophytes, and arthritis of the vertebral joints; (iv) Lumbago is a contracture of the paravertebral and lumbar muscles as a consequence of irritation of the lumbar nerve by displacement of the disc nucleus. It is installed suddenly and painfully; (v) spinal stenosis occurs as a result of degenerative diseases that cause changes in the joint areas, which decreases the space of the spinal canal. The damage occurs at both the cervical and the lumbar levels.

The recovery of these diseases of the spine is done through recovery therapies such as massage, ultrasound therapy, electrotherapy, laser, teak therapy, shockwave, cryotherapy. For the use of these therapies, medical recovery equipment is used to reduce the inflammation, pain, and edema present in the joints, muscles, and ligaments of the spine.

Over time, it has been found that the main diseases of the spine that cause long-term physical disabilities in adults are stroke and spinal cord injury.

Regarding the survival rate, approximately 10 million people survive trauma after stroke and over 250.000 survive after spinal cord injuries.

This is due to post-stroke activation deficiencies, which limit their self-reliance. Also, as a result of injuries to the central nervous system, there are side effects such as spastic muscle tone.

Compensating for sensorimotor deficiencies is spasticity, an aid in restoring lost function. Thus, spasticity has been clinically proven by studies that can be used to partially reduce the loss of limb activation in mobile patients, and spastic legs may act as a support for the body while walking or in maintaining a stick-like position [7]. These statements are valid only for moderately affected patients, while for those with severe disabilities, spasticity and muscle cramps require pharmaceutical interventions due to their exaggerated intensity.

Statistically, at European level, there have been 200 cases of stroke in 100,000 people reported. Of these records, 10% integrate into society, 40% remain with moderate sequelae, 40% have severe sequelae, and 10% are unrecoverable.

Recovery from conditions such as stroke and multiple sclerosis and last but not the least spinal cord injuries have a difficult goal to define, because conventional therapies hardly separate the spontaneous recovery of function that occurs with rehabilitation treatment. In post-stroke recovery, the motor recovery process takes place mostly in the first 3 months and at 6 months with little measurable progress.

Depending on the time of the stroke and the time of recovery, several phases can be defined: (a) initial phase (acute); (b) medium phase; (c) advanced phase.

In the acute post-stroke phase, functional improvements dependent on the stabilization of the brain injury, such as the reduction of edema, can be determined. Subsequently, neurological recovery occurs through a process of structural and functional reorganization of the central nervous system called neuroplasticity.

After stroke, multiple functional deficiencies are installed, and among these we present the following:

Motor impairments associated with lack of strength, balance, and coordination (paresis, paralysis); affections of superficial sensitivity (tactile and thermal with different degrees of hypoesthesia) with deep and mixed sensitivity; sensory, perceptual, and cognitive impairments and deficits; painful disorders from peripheral neurological disorders (neuralgia, neuritis) and central neurological disorders (thalamic pain); vegetative disorders; impaired osteotendinous reflexes in central motor neuron syndrome; dysarthia, dysphagia, aphagia.

Neuroscience studies have made clear progress, showing that the human brain is capable of plastic rehabilitation after injury [8].

The purpose of neurorehabilitation is to use the maximum capacity the quality of neuroplasticity, which is limited, but most people recovered reach a plateau of 70–80% of the initial post-stroke damage. Thus, as an uncomfortable recovery, compensatory movement strategies are applied, which help to alleviate motor deficiencies, for example, the use of a wheelchair [21].

The entire recovery of the motor function of a person with central nervous system injuries becomes a re-learning process, which uses the preserved sensorimotor circuits. The severity of lesions of the central nervous system and the individual neural capacity of the patient are the important aspects for re-learning and training of neural circuits in order to restore normal movement patterns.

5. Spinal cord injuries

Spinal injuries often cause serious injuries, due to their complexity, but also due to the neurological complications associated with them.

Thus, we mention that 40% of the injured people have cervical fractures, 15–20% have lumbar thoracic fractures, and in most cases, there are neurological lesions.

Statistically, trauma is caused by the following: 45% of road traffic accidents (car, motorcycle); accidents that occurred during work (falls from a height) in proportion of 20%; accidents in performance sports in the proportion of 16%; direct injuries caused by a firearm in the proportion of 15%; other types of trauma in the proportion of 4%.

In the case of people after the age of 75, about 60% of spinal fractures are due to falls from the same level below the evolution of osteoporosis.

Therefore, spinal cord injuries (SCIs) have an increased incidence, which lead to increased disability and lethality with difficulties in diagnosis and treatment by complex surgical procedures.

The percentage of vertebra-spinal cord injuries is, according to statistics, between 0.5 and 20% in the structure of the skeletal system and 10.5% in the structure of the nervous system.

The main location of spinal cord injuries is the thoraco-lumbar junction as shown by the following data: 12.3 of the injuries are located in the cervical area; 39.2% of injuries are located in the dorsal region; 48.5% of injuries are in the lumbar area; 25% T12 vertebrae for the dorsal region; 30% of the L1 vertebra in the lumbar region.

From a lethal point of view, the percentage reaches 34.4% for myeloma traumas, 8.3% for the dorsal region, 6% for lumbar traumas, most of which are with neuronal damage, with a disability of 95–98% of cases [19].

The mechanisms of trauma are generally by indirect mechanisms (95%), by the combined action of several forces, of different sizes, as follows: (1) Hyperflexion is the movement of excessive inclination in the anterior part of the transverse axis of the spine through the segment of movement. This movement performs a flexion, compression of the intervertebral bodies, and discs causing fractures by compression with the previous deformation of the vertebral body. The frequency of this type of trauma due to hyperflexion occurs in traffic accidents with frontal collision or by falls from a height; (2) hyperextension is the exaggerated tilt movement of the transverse axis of the segment in the back, common in the cervical vertebrae. Mechanism is caused by sudden rear-end traffic accidents and frontal collision accidents. Thus, this movement performed suddenly requires extension of the vertebral arches and produces compression, in unilateral or bilateral fractures of the bone elements; (3) pure compression is common in head-on sports accidents, head-on falls, or catapults in the cockpit. This axial compression of the anterior elements of the spine causes fractures of the vertebral body with centrifugal displacement of the fragments, especially when the spine is straight; (4) lateral hyperflexion puts pressure on the anteroposterior axis segment by making a forced frontal tilt either to the right or to the left. This movement is perfectly combined with rotation, in this case causing compression bone fractures (compression fractures) ligament injuries by traction; (5) shearing is obtained by the translational movement of parallel displacements of one vertebra over another, causing the destruction of the segment. The occurrence of this type of mechanism is especially in accidents involving the application of a ortho force on the spine (serial tamponade); (6) torsion is the twisting movement by rotating the motor segment, which causes dislocations of the intervertebral joints, but also severe sprains with spinal cord and joint complications.

Spinal cord injuries can cause a variety of pathologies, depending on the impact of the injury. Thus, the basis of these traumas is medullary or radicular neurological changes caused by symptoms, which overlap with the spinal shock (reversible loss of all spinal cord functions).

Injuries are classified as closed or open, with or without bleeding, with or without fractures, and stable or unstable.

The unstable injuries are dislocations between the spinous processes, dislocations of the vertebral arch, articular apophyses, vertebral blades, vertebral pedicles [22].

The effects of trauma and subsequent illness are as follows: Peripheral nerve palsy is a condition that can be acquired through a spinal cord injury or other causes such as diabetes, lead poisoning, alcohol. The symptoms are presented by muscle deformities, loss of muscle tone, lack of normal coordination of movements; paraparesis is an incomplete paralysis of the limbs due to spinal cord injury. It can be flaccid or spastic: vertebral fractures of vertebral bodies and arches. Stable fractures are those of the spinous, transverse processes, and vertebral body fractures, at which the settlement is below one third of the height of the vertebral body.

6. Methods and techniques of spine recovery

The methods and techniques of spine recovery are performed in specialized centers that offer sports and medical recovery programs for prophylactic, curative purposes, through physical, dynamic, and static exercises. The condition that the patient suffers from post-trauma, as well as its severity, orients the recovery plan toward muscle stimulation, improvement of muscular endurance, rehabilitation of diminished functions (balance, coordination, control, mobility).

From the point of view of post-trauma investigations, X-ray of the spine segment is performed to detect fractures, electrocardiogram for routine, tomography as an additional investigation, computed tomography for the skull, but also ultrasounds and Doppler for people with costal contusions.

The operative indication comes against the background of unstable fractures and medical urgency with the interest of the spinal cord.

From an orthopedic point of view, the treatment of thoracic spine injuries involves immobilization in the corset-lombostat and the small or large Minerva for cervical spine injuries. If the patient cannot be lifted and placed in the corset, a plaster bed mobilization is performed.

The initial goal in neuromotor recovery treatment is as follows: respiratory system; syndrome of vertebral insufficiency with painful symptoms, treated by physical therapy, massage, electrotherapy, and heliomarine cure; reduced urinary disorders by bladder re-education and acupuncture; motor deficits (paraparesis/folds, tetraparesis) with a re-education through physiotherapy and robotic equipment (Lokomat) with a variable duration of 3–5 years.

To ensure a complete recovery, treatment is essential in ensuring the natural healing processes. Thus, therapeutic methods include special techniques for soft and joint tissues, therapy with physiotherapy equipment, and pre- and post-treatment evaluation.

Immediate treatment of acute trauma involves reducing the inflammatory reaction by protection (immobilization in orthoses or plaster cast), rest, ice, compression, and lifting the limb above the horizontal plane.

The methods and techniques used to recover the spine are as follows: (a) Joint mobilization techniques are performed passively by the therapist or equipment, with the aim of restoring total mobility, and may be successfully combined with other soft tissue therapy and joint stabilization techniques; (b) essential muscle training techniques in the stagnation of muscle atrophy installed quickly post-trauma are applied depending on the type of trauma. Thus, the effort and the possibilities of loading are performed by increasing the speed of movement, endurance, the number of repetitions, or by changing the shape of the exercise. They can be performed simply under the guidance of a therapist or by using robotic infectious equipment or grounded platforms (Lokomat, Mit Manus); (c) strength training techniques; isometric, isotonic, isokinetic, with resistive band, with different resistances. Isometric training involves performing 5–10 maximum contractions per day, in order to protect the joints from stress and reduce inflammation. Isotonic training allows you to perform stretching exercises to prevent compressive forces on the affected joints. Training with bands of different resistance applied in multiple movement plans have an effect on stimulating the functions and actions specific to the area worked; (d) the manual techniques used in recovery are intended to relieve symptoms and improve the functioning of the spine. We can talk about the use of manual therapy techniques, massage, acupuncture, or presupposition, all of which treat the problems of the spine. Massage techniques are performed between the proximal to distal segments, with the aim of improving blood circulation, reducing inflammation and edema, but also to maintain the muscle tone of the surrounding areas. The application of manual therapy with addressability for the joint, muscular, and nervous areas is carried out with the aim of identifying the areas with joint pain or limitation and reducing them through manipulation, mobilization, or traction techniques. Acupuncture consists of applying a force of tension with the help of the fingers (thumb) on selected muscle areas for the purpose of stimulating muscle receptors, relieving symptomatic trigger points, and activating muscle tone by releasing substances necessary to reduce pain. Dry needling or acupuncture is the method of inactivating trigger points in chronic musculoskeletal syndromes. The method is performed by inserting needles perpendicular to the skin, which results in a muscular reflex response and increased post-treatment mobility; (e) proprioception and coordination re-education techniques represent the final phase of spine recovery, with the training of movements essential for the basic activity of the injured patient.

The benefits of using physical therapy in spinal recovery are as follows: Reduction of pain, stiffness of joints, and muscles; improving posture, balance, and coordination of the entire muscle and joint chain; recovery of acquired physical deficiencies after trauma (stroke, CVD); reintegration of patients into pre-trauma activities.

From the point of view of the technologies involved in the recovery of the spine and the neuromotor recovery of the spine, we mention the following: (i) training with treadmills with partial support and with the help of robots (Locomat, Armeos, Mit Manus); (ii) stimulating neuroplasticity using vibrating devices for the whole body (Galileo, Zeptor) and stimulating the healthy limb through Wii consoles; (iii) transcranial magnetic stimulation or direct currents with the neural helmet for the treatment of aphasia after stroke; (iv) electrotherapy with shock in reducing symptoms shows the use of ultrasound therapies, interference currents, shockwave, laser therapy, iontophoresis, as well as the combined technique.