Continuing Education Activity

High-velocity low amplitude (HVLA) techniques employ a rapid use of force over a short duration, distance, and/or rotational area within the anatomical range of motion of a joint to engage the restrictive barrier in one or more planes of motion to elicit the release of restriction. This activity outlines high-velocity low amplitude manipulation techniques and explains the role of the healthcare team in improving care for patients who undergo HVLA manipulation.

Objectives:

• Describe the common terminology associated with HVLA.
• Identify the common complications of HVLA procedures.
• Summarize the proper procedural considerations for HVLA manipulation.
• Outline the prevalence of HVLA procedures.

Introduction

Dr. Kirkaldy-Willis first conceptualized and published theories regarding the Biomechanics and Biology of the Spinal Degenerative Cascade. He defined the HVLA technique as "a skilled, passive manual therapeutic maneuver during which a synovial joint is beyond the normal physiological range of movement (in the direction of the restriction) without exceeding the boundaries of anatomical integrity."[1]

High-velocity low amplitude techniques employ a rapid use of force over a short duration, distance, and/or rotational area within the anatomical range of motion of a joint to engage the restrictive barrier in one or more planes of motion to elicit the release of restriction. This manipulation technique uses high velocity and low amplitude thrusts to manipulate joints. Osteopathic physicians, chiropractors, and physical therapists are trained in HVLA and commonly perform these techniques. 

Both therapies are used in cases of acute musculoskeletal back pain. The physician positions the person at the barrier of limited movement and then gives a rapid thrust in the isolated barrier's direction to resolve the restriction and improve motion. This method is among the oldest and most frequently used, and it is among the most common types of complementary medicine for children. Most clinical research has focused on evaluating the efficacy of this form of manipulation, particularly for low back, mid-back, and neck pain.

Purpose — restore motion to a restricted joint and improve function. 

Terminology

High-velocity low amplitude is interchangeable with manipulation and thrust because of the different biomechanics. Nevertheless, these all unify in describing the process of increasing the range of motion. 

• Abbreviations — (AOA) American Osteopathic Association; (DO) Doctor of Osteopathic Medicine; (HLVA) High-velocity low amplitude; (HVLA-SM) High-velocity low amplitude spinal manipulation; (L) Lumbar; (ms) milliseconds; (N) newtons; (OMT) Osteopathic Manipulative Treatment; (RCT) randomized controlled trials
• Adverse Event — Stroke, headache, joint pain, and vertebral artery dissection are possible adverse events associated with an HVLA OMT technique.
• Amplitude — The thrust's distance attempts to create a movement of about 1/8th inch at the joint treated.
• Cavitation — The process of using a mechanical force to precipitate a gas bubble in a joint space.
• Fulcrum — This describes when a hand or body localizes a thrust's force into the segment or joint that is restricted.
• Long Lever — The extremities or multiple segments of the vertebral column. 
• Manipulation — Synonym for a high-velocity low amplitude technique. Manipulation occurs at the end of and often beyond the available motion of the joint to break adhesions that disrupt or prevent joint movement. 
• Short Lever — Any portion of the vertebra held while force is applied to the adjacent vertebra's bony prominence.
• Thrust — Synonym for a high-velocity low amplitude technique. Thrust may refer to cracking or popping sounds. 

Statistics

• Prevalence Of Use Amongst The Pediatric Population: 2 to 3% [2] 
• Approximately Incidence Adverse Event Per OMT Procedure: 1/50,000 [2] 
• Approximate Number of Adverse Events Which Are Operator-Induced: 1/5 [2] 
• Approximate Number of Adverse Events In Cervical Manipulation: 1/400,000 to 1,000,000, 1 every 177.5 weeks [2] 

Anatomy and Physiology

Spine and Vertebra

Five vertebral segments and their respective nerve roots exit under the respective vertebrae in the lumbar spine. For instance, the L3 nerve leaves the foramen of L3 and L4. When a patient experiences pain radiating down a given dermatome, therapies focused on nerve fibers, including associated spinal segments, might be viable to adjust to that area. 

Small joints, such as zygapophyseal joints, have synovial joints on the upper and lower surfaces of the vertebrae. The upper facets are centered on the back and medial joint surface and interface with the contiguous vertebras' related joint surface. This structure results in flexion and contraction in contrast with rotation or horizontal bending of the vertebral motion's remainder. This reduced flexibility for lateral stretching guides the vertebrae to be manipulated in lumbar HVLA. Spinal therapy is the most common method of manual care used to correct musculoskeletal disease.

This process is very clearly separated from spinal mobilization by an external thrust. Hence, it is fair to assume that these two modes of therapy can have an equal impact and should thus be investigated separately, either clinically or through their modes of action. Usage results show that comparatively high speed and low amplitude manual procedure occurs for most patients who undergo spinal manipulation. The health care worker immediately transmits a thrust to the target vertebra by a small lever arm following preloading of the vertebra tissues by physically touching the skin that is overlaid by the lamina, spiny, transverse, or laminar mechanism to move the vertebra, gap its facet joints and produce mechanical, physiological, biological results.

An analysis of clinical evidence showed that spinal manipulation could help respond to back pain, migraine, pain in the spine, upper and lower extremities, and whiplash-related disorders for many conditions. In specific adaptations, the whole spine or significant parts of it are controlled as a unit; others are small motions intended to impact a particular joint.[3][4]

Biomechanics

HVLA strategies aim to re-establish normal joint operations. They use a thrust force that hits a height from 220 to 889 N in a range of 75 to 225 mm that moves the vertebral, separates the facet joints, and causes mechanical, neurological, and biological effects. Up to 10 mm from the initially planned location is the initial point of contact. However, it is uncertain what significance these improvements have on the pathways underlying the efficacy of HVLA.[5][6] 

Neurophysiology

A physiological barrier is a point at which soft tissue stress restricts the voluntary range of movement in an articulation. If the joint crosses a physiological barrier, it may cause additional movement to the anatomical barrier. The anatomical barrier is when the bone curvature or body tissues (notably cartilage) become restricted to the passive range of motion. The anatomical barrier is the final limit of motion in the joint. Tissue damage can result from movement outside the anatomical barrier.[2] 

An increasing body of reviewed literature indicates that neurophysiological changes occur after spinal stimulation, including neural plastic changes, motor neuron excitability alteration, and cortical drive increase. One hypothesis is that the dispersion of carbon dioxide and nitrogen restores mutual function. In its liquid form, carbon dioxide displaces a joint from its regular location. During a manipulative motion, the velocity created a guided force-the absorption of nitrogen, turning them from a liquid into a gaseous state and allowing the joint to return to normal articulation; this indicates that the range of motion is increased by cavitation.[7]

Carbon dioxide is dispersed by cavitation, which leads to audible joint pop. The vasodilatory effects of carbon dioxide promote increased blood flow, chemotaxis, and cell-attaining nutrients. The joint's popping often follows a manipulative motion. Crack noise or joint cavitation results from a gaseous bubble in the synovial fluid producing or collapsing. Cineradiographic studies have documented increased joint space and production/breakdown of carbon dioxide gas after thrust manipulation. Since carbon dioxide is the gas with the highest miscibility in the synovial fluid, this rise in carbon dioxide levels has been suggested as the mechanism for raising the range of motion after manipulation in the joint. 

It has also been hypothesized that any reflex relaxation of the periarticular musculature will initiate the cavitation. After the manipulation, the joint takes about 15 minutes to rearrange the gas particles and make another cavitation sound. Some people believe that nothing has changed because there is no noise; this assumption is often incorrect. Recent findings indicate no correlation between the presence of an audible pop in patients with non-radicular low back pain during joint manipulation and improvement in pain, ROM, and impairment.[5]

There are several hypotheses from a physiological perspective as to why HVLA is an efficient method of care. First, an HVLA thrust tends to stretch a contracted muscle, which, in turn, creates many afferent impulses to the central nervous system from the muscle spindles. The central nervous system then reflexively sends an inhibitory impulsion to the muscle spindle to relax the muscle. An alternative hypothesis suggests that the Golgi tendon receptors become activated instead of the muscle spindle, eventually relaxing the muscle.[1]

Indications

Findings That Suggest An Individual Might Recieve Therapeutic Benefit From HVLA

• Low back pain for 16 days or less/ more recent onset of low back pain.
• Hypomobility of the lumbar spine.
• All joints showing hypo-mobility

Findings That Suggest An Individual Might Not Receive Therapeutic Benefit From HVLA

• Symptoms behind the knee
• Low back pain episodes increasing frequency
• High back pain is recurring or chronic.
• Just low back pain (no distal symptoms); no knee pain
• Peripheralization of action knee pain
• High scoring questionnaire values based on the presence of conditions such as, for example, the use of anticoagulant drugs, chronic osteoarticular pathologies, or traumas that alter the morphology of the joint, unspecified pain, recent surgery, and all conditions of clinical instability
• No spring test pain.

Eligibility

Not to render manipulations:

• If osteoarthritis or osteoporosis is severely present in the spine
• If tumors or malignancies arise in the area
• If blood flow deficiency occurs inside the vertebral artery in the cervical field
• If a joint is bloodied
• If the joint has a loose body
• Max mutual substitutions
• Joints close a forum for the development
• Where a degenerative joint is present
• To reach a complete diagnosis

Contraindications

A contraindication is if the chance of damage to the patient exceeds its potential benefit. Indirect methods result in less risk for patients with acute injuries, serious diseases, undiagnosed disorders, or vulnerable conditions. The body is pushed away from the restriction into a tissue laxity position. In these conditions, direct strategies wherein the transition occurs towards a restriction are far less applicable but are adequate and appropriate in many chronic diseases.

Absolute Contraindications with Clinical Instability

Meningitis; dislocations; bone disease; cancer; cardiac diseases; rejection by patients, for example, thrombosis; nerve-damaged neurological disorders, damage to the spinal cord, and serious intervertebral disc-prolapse.[8][9]

Relative Contraindications

Ankylosing spondylitis, anticoagulant treatment, atherosclerosis, aspirin, warfarin, bone fracturing disorders, Down syndrome, heparin, herniated disk, hypochondriasis, hysteria, eptifibatide, Malingering, nerve root compression, osteoarthritis, osteoporosis, Patient hesitation, clopidogrel, extreme discomfort, ticlopidine, vertigo, extreme sprains, and strains.[8][9]

The HVLA technique is not allowed by students due to the possible danger of regularly treating a uniform patient with a thrusting process to the same section on a given day. A 2010 analysis found that HVLA used less than 0.01 percent of cases out of 24,202 OMT documented instances.[10]

Equipment

The patient can be put on a cushioned bench specifically built to help therapists maintain the proper care configurations. Although the hands are normally used, certain therapists might employ a tool to help with the adjustment. Specially designed chairs and tables may be used to position the patient.[5]

Electromyography

This device can be used to ensure a regulated, recurring, quantifiable HVLA technique. Studies have shown that a rise in thrust intensity produces linear changes in the magnitude of electromyography responses evoked before and after the deceptive thrust.[11]

Personnel

 The staff who apply this manual approach must have a previous internship process.

Preparation

Staff preparation includes a thorough theoretical and practical study of manual methodology.

Patient preparation is linked to the description of the procedure and the patient's consent.

Technique or Treatment

Methods

1. Identify restricted joint movement for all possible planes of motion
2. Move the joint into its restriction for all planes
3. Apply a short quick thrust through one of the restricted joint planes
4. Retest motion

Techniques

Diversified — This method is the high-speed, low-amplitude route typically synonymous with manual physiotherapy corrections. For this procedure, therapists use a fast torque (low amplitude) throughout varying joints to recover the flexibility and mobility range throughout the joint. The body of the patient is put in particular forms to maximize the spinal change.[5]

Palmer Gonstead Adjustment — Although the Gonstead adaptation is an HVLA adaptation, close to the previous technique, it varies in the assessment (localization) of the target joint and joint localization parameters. To position the patient, devices such as the cervix chair or the chest-knee table, specially built chairs, and tables can be used.[12]

Thompson Terminal Point —This technique involves physiotherapy treatment tables with areas that fall short distances through an HVLA threshold, thus promoting mobility by minimizing the table's component. This modification strategy is also used in preference or for a combination of more conventional diversified HVLA modifications. This may or may not have the typical "cracking tone," so this coercion method may also be viewed as a form of mobilization or gentle adaptation.[12]

Alternative Lumbar Manipulation — Other HVLA techniques do not explicitly fall into a direct or indirect model. Some techniques include soft tissue manipulation, which is essentially a massage technique that reduces muscle tension. For illustration, to make HVLA convenient, we typically make the area with soft tissue techniques before conducting HVLA.[13]

Balance and Control — The practitioner and patient must have a reasonably relaxed, comfortably controlled, and secure posture in their body. For optimum placement, the table should be at the appropriate height. The patient has to be put on the table properly. While conducting the thrust, the patient should be calm. The thrust is better applied with (1) leverage used to change the joint with the hand and/or forearms and (2) to position and focus the thrust into a particular joint.[5]

Complications

Patients' temporary side effects from manipulation can persist undetected if nonspecific guidance to patients is provided aftercare. Prospective research has estimated that approximately 30 to 61%  of patients encounter typical side effects arising from spinal stimulation.[14][15][16] 

Most often, localized tightness, headaches, weakness, soreness radiating, numbness, dizziness, exhaustion, rigidity, body warmth, and consciousness loss. Premature or severe menstruation, gastrointestinal discomfort, twitching, dysrhythmia, and sweating are the least frequent.[17] These intermittent side effects generally occur about 4 hours after therapy and then improve throughout the following 24 hours.[16] 

A few individuals may develop a slight headache after cervical manipulation or soreness after back stimulation. In persons with delicate skin, some erythema and petechiae may occur, which may persist for hours. As therapy progresses, some problems can resurface, and when treatment is interrupted, effects can worsen.

Clinical Significance

Clinical Goals

• Increase the movement capacity of a confined joint
• Realignment of skeletal components to recover natural joint receptor function at the treated level
• Reduce the hypertonicity of muscles and/or spasms to restore equilibrium to the joint-related muscles
• Extension of the joint-related reduced connective tissue

Research — HVLA thrust techniques are commonly considered potentially riskier than other techniques because of their accelerated thrust and force operation.  As a result, the bulk of research focuses on the adverse HVLA effects.  The most important side effects associated with HVLA are those that combine high-velocity thrusts with rotational techniques or anesthesia. Self-rotation or involuntary turning of the head has also been associated with sudden and unintended injuries. In a study that looked at 283 reviews, only 118 produced adverse results. Strokes, headaches, and vertebral artery dissection were the most commonly described adverse effects. Of the 118 investigated, 46% indicated that HVLA is safe, 13% indicated that HVLA was harmful, and 42% were neutral or unknown to the effects of HVLA.[11] 

The American Osteopathic Healthcare Association focuses on the continual investigation of patient treatment, hospital visits, chronic pain, women's chlamydia infection, deep venous thrombosis, and elderly fall prevention, in addition to the many above conditions.[11]

Enhancing Healthcare Team Outcomes

Skills

Teaching aids improve skill-based outcomes, patient safety, and overall team performance among physicians, nurses, pharmacists, and other health professionals. Studies have shown that teaching aids can improve the rate of skill acquisition. Additionally, it appears that mentoring, coaching, and feedback, in addition to training aids, are the most efficacious.[18][19] [Level 4]

Strategy

A cost-benefit-based approach to HVLA training amongst physicians, nurses, pharmacists, and other health professionals appears to be best. There is a significant gap in the cost-to-benefit ratio, such that teaching aids might be most effective within a defined curriculum structure. Studies seem to suggest that early implementation leads to longer-lasting consistency. At the same time, downstream implementation enhances more technical aspects of manipulation. Timing is an important consideration when designing curricula for training programs. Using lower ratios of contact hours and teaching aids to augment practice may result in better performance gains when introduced later than if added early in the curriculum. Teaching aids and a hands-on approach may result in better performance gains when introduced later in the curriculum than earlier for programs with lower contact hours.[1][20] [Level 4]

Ethics

To enhance the ethical aspects of HVLA in patient-centered care, clinicians, nurses, pharmacists, and other health professionals should consider the legality of HVLA techniques. One study summarized the various legal challenges. A survey of California disciplinary data showed a case rate of 4.5 per 1000 chiropractors a year compared to 2.27 per year for physicians, with fraud incidents nine times higher among chiropractors (1.99 per 1000) than among physicians.[21] [22] [Level 5]

Responsibilities

To enhance the role HVLA has in patient-centered care, physicians, nurses, pharmacists, and other health professionals must strive for uniformity. A study investigated the significance of uniform standards. One study looked at the Gonstead technique in 81 simulated adjustments on a mannequin force plate. Analysis of over 800 thrusts showed wide variations in peak loads. Thrust rates are most consistent amongst clinicians. To improve the role HVLA has in outcomes, patient safety, and overall team performance, physicians, nurses, pharmacists, and other health professionals should therefore focus on reproducibility. While reliability is relatively high for manual rotational HVLA thrust on C1-C2, reliability for flexion-extension and lateral bending remains low.[23][24][25] [Level 4]

Interprofessional Communication

Clinicians, nurses, pharmacists, and other health professionals must also consider how the general public views manipulation and HVLA techniques. A paper described some of the views concerning cervical spine manipulation. HVLA is viewed unfavorably by mainstream medicine. Approximately 36% of respondents considered HVLA favorably.[26][27] [Level 5]