Table 2. Summary of Studies Examining the Effects of HVLA Techniques.

HVLA: High velocity low amplitude

AUTHOR - YEAR	INTERVENTION	SAMPLE	METHOD	RESULTS
Oliveira-Campelo et al., 2010	Manipulation group: atlo-occipital joint thrust. Soft tissue group: sub-occipital muscle inhibition technique. Control group: no intervention.	122	Absence of pain, maximum active mouth opening and pressure pain threshold.	The manipulation of the atlo-occipital joint produces an immediate increase in the pain threshold at the pressure of the trigger points on the masseter and temporal muscle and increases the minimum opening of the mouth.
Mansilla-Ferragut et al., 2009	Manipulation group: thrust atlo-occipital joint. Control group: manual therapy	37 women	Absence of pain, maximum active opening of the mouth and pressure pain threshold.	The application of a thrust to the atlo-occipital joint results in an increase in the maximum active opening of the mouth and the pressure pain threshold.
Martinez-Segura et al., 2006	Experimental group: HVLA thrust. Control group: manual mobilization.	70	The assessment was carried out at rest and 5 minutes after treatment.	A single cervical manipulation is more effective than controlled mobilization in reducing resting neck pain and increasing the active range of motion in people with neck pain.
De Camargo et al., 2011	Handling group: thrust C5-C6. Control group: no treatment	37	EMG data of deltoid muscle, increased pain threshold at pressure of upper trapezius muscle, deltoid and C5 spinous process.	Patients in the manipulation group achieved an increase in the pressure pain threshold on both the deltoid and the C5 spinous process, this was not the case on the upper trapezius. At EMG on the manipulation group there was an increase in median frequency at the beginning of the isometric deltoid contraction.
Dunning et al., 2008	Single thrust group on the right C5/C6 zigoapophyseal joint and placebo group	54 asymptomatic	Pre and post C5/6 Thrust using DelSys Surface EMG system.	Immediate increase in EMG activity at rest of the biceps bilaterally, regardless of whether cavitation occurs or not.
Fernández-Carnero et al., 2008	The subjects participated in two experimental sessions in two separate days, at least 48 hours apart. At each session, participants received a randomly assigned manipulative or manual contact intervention.	10	Thermotest system, electronic algometer and dynamometer.	The application of a manipulation to the cervical spine produced an immediate bilateral increase in the pressure pain threshold and reduction in grip pain. There were no significant changes in pain compared to heat/cold and grip strength on the healthy arm.
Botelho and Andrade, 2011	The subjects were randomly divided into two groups: cervical vertebral manipulation and simulated treatment.	18 men (judo athletes)	The force measurements were obtained from a hydraulic dynamometer immediately before and after each intervention.	Gripping force improves after cervical vertebral manipulation.
Ruiz-Sáez et al., 2007	Two groups: 1) manipulative group and 2) placebo group, simulated treatment.	72	A pressure algometer was used to measure the increase in pain threshold at the pressure.	After a single manipulation at C3-C4 level the pressure pain threshold on the latent trigger points of the upper trapezius muscle immediately increases.
García-Pérez-Juana et al., 2018	Subjects were randomly divided into two groups: Group 1: cervical manipulation (right or left), Group 2: fictitious manipulation	54	Immediate outcomes included cervical kinaesthetic sense as evaluated by joint position sensing error (JPSE) and pressure pain thresholds (PPT). At one week, the results of neck pain intensity (numerical pain scale) and neck pain-related disability (Neck Disability Index [NDI]) were also collected.	Mixed model analysis of covariance revealed significant group × time interaction in favor of the cervical thrust manipulation group for JPSE on rotation and extension. There was also significant interaction for PPT changes from C5 to C6 and anterior tibial. At the one-week follow-up, there was a significant interaction for neck-related disability but not for resting neck pain, worse pain or lower pain experienced in the previous week.
Griswold et al., 2018	Compare non-thrust (NTM) and thrust (TM) manipulation on the cervical and thoracic tract for mechanical neck pain	103	The Neck Disability Index (NDI) was the main result. Secondary outcomes included the Patient Specific Functional Scale (PSFS), Numerical Pain Scale (NPRS), Deep Neck Flexural Strength (DCF), Global Assessment of Change (GROC), number of visits and duration of care.	NTM and TM produce equivalent results for patients with mechanical neck pain.
Galindez-Ibarbengoetxea et al., 2018	Comparing the immediate pain effects of a treatment using HVLA manipulation versus single use of a CCF exercise protocol.	25	Measurements included (1) a visual analog scale (VAS) completed during the measurement of range of motion (ROM), (2) an assessment of cervical spine ROM, (3) a pressure pain threshold test (PPT), and (4) electromyographic activation (EMG) of the sternocleidomastoid muscle during a craniocervical flexion test.	Although both interventions were associated with ROM and pain immediately improved after treatment, HVLA manipulation was more effective than CCF exercise in improving ROM and VAS during ROM. None of the interventions led to changes in EMG.
Alonso-Perez et al., 2017	Subjects were randomly assigned to receive: low amplitude high velocity technique (HVLA), joint loosening or cervical lateral glide loosening (CLGM).	75	The pressure pain threshold (PPT) on C7 unilaterally, the trapezius muscle and bilateral lateral epicondyle were measured prior to application of the single MT technique and immediately after application of the MT. Pain catastrophe, depression, anxiety and kinesiophobia were assessed prior to treatment.	The results indicate that hypoalgesia was observed in all groups after treatment in the neck and elbow region (P < 0.05), but loosening induces more hypoalgesic effects. The interaction between catastrophication and HVLA technique suggests that if the level of catastrophication is low or medium, the chances of success are high, but high levels of catastrophication can cause poor results after HVLA intervention.
Bautista-Aguirre et al., 2017	Cervical or thoracic HVLA. The comparison was made with fictitious contact.	88	It was assessed whether there was an influence on the pain threshold at median/ulnar/radial pressure after the execution of the manipulative techniques. Secondary measures included the assessment of painless gripping force.	Manipulation of low cervical and upper thoracic thrust is no more effective than placebo to induce immediate changes in nerve trunk mechanosensitivity of the upper limbs and gripping force in patients with chronic non-specific mechanical neck pain.
Langenfeld et al., 2015	Manual and mechanically assisted manipulations of the thoracic spine compared.	54 participants with acute or chronic neck pain	The primary measure was pain intensity (VAS). Secondary outcome measures are the physical disability of the neck using the Neck Disability Index, the quality of life measured by European Quality of Life Levels 5 Dimension 5 and patient improvement using the global scale of the patient's impression of change.	Both surgeries improve the neck pain. This is a significant result, as manipulation of the thoracic spine for neck pain does not pose the same risk of injury as manipulation of the cervical spine.
Erhardt et al., 2015	The intervention group received high velocity thrust (HVT) at the atlanto-axial segment while the control group was held in the pre-manipulative waiting position.	23 healthy participants	Color flow Doppler ultrasound was used to measure hemodynamics VA3.	HVT in the atlanto-axial joint segment does not affect the hemodynamics of the sub-occipital portion of the vertebral artery during or immediately after HVT in healthy subjects.
Coronado et al., 2015	Three treatments: cervical TM, shoulder TM or shoulder exercise for over two weeks.	78 participants with shoulder pain	The treatments were compared to 25 healthy participants to compare pain sensitivity with that of the clinical baseline participants.	Clinical participants showed increased sensitivity to pain, but did not respond differently to cervical or peripheral TM.
Saavedra-Hernández et al., 2013	One group performed only cervical manipulation and the other the combination of cervical, cervicothoracic and thoracic manipulation.	82 participants with mechanical neck pain	Neck pain intensity, self-reported disability and cervical range of motion were collected at baseline and one week after the intervention of an assessor blinded by patient allocation.	In patients with chronic mechanical neck pain, cervical and thoracic spine manipulation leads to a greater reduction in disability at one week compared to cervical spine manipulation alone, while changes in pain and range of motion are not influenced differently.
Martínez-Segura et al., 2012	Three groups were formed: the first received cervical manipulation on the right, the second on the left and the third thoracic manipulation.	90 participants with bilateral mechanical neck pain	Pressure pain thresholds (PPT) above the C5-6 zygapophyseal joint, lateral epicondyle and anterior tibial muscle, neck pain (11-point numerical pain assessment scale) and cervical spine interval of motion (CROM) were collected at baseline and 10 minutes after surgery by an assessor blinded by patient treatment assignment.	The results of the randomized clinical trial suggest that cervical or thoracic thrust manipulation induces similar changes in PPT, neck pain intensity and CROM.
Dunning et al., 2012	Patients were randomized to receive or manipulate HVLA or mobilization to the upper cervical and thoracic vertebrae.	107 participants with mechanical neck pain	It was evaluated at baseline and after 48 hours: the neck disability index, the numerical pain assessment scale, the flexion rotation test for measuring the C1-2 passive rotation range of motion and the craniocervical flexion test for measuring the motor performance of the deep cervical flexor.	The HVLA group had a greater reduction in pain disability than the mobilization group. In addition, the HVLA group had a significantly greater improvement in both the C1-2 passive rotational movement range and the motor performance of the deep cervical flexor muscles than the group receiving mobilization.
Puentedura et al., 2011	One group received thoracic manipulation and a cervical range-of-motion (ROM) exercise for the first two sessions, followed by a standardized exercise program for another three sessions. The other group received cervical manipulation and the same cervical ROM exercise for the first two sessions and the same exercise program given to the thoracic group for the next three sessions.	24 participants with acute neck pain	The outcome measurements collected one week, four weeks and six months after initiation of treatment included the Neck Disability Index, Numerical Pain Assessment Scale and Fear-Avoidance Beliefs Questionnaire.	Patients who received cervical manipulation demonstrated greater improvements in the Neck Disability Index and Numerical Pain Scale scores at all follow-up times. There was also a statistically significant improvement in the Fear-Avoidance Beliefs Questionnaire physical activity score at all follow-up times for the cervical group.
Fernández-de-las-Peñas et al., 2007	Each subject participated in three experimental sessions on three separate days, at least 48 hours apart. At each session, subjects received the C5-C6 cervical manipulation intervention, placebo or control provided by an experienced therapist.	15 healthy participants	The immediate effect on the pressure pain threshold on the lateral epicondyle of both elbows, both preoperative and 5 minutes post-operative, was assessed.	The application of C5-C6 cervical manipulation produced a greater increase in PPT in both elbows, compared to placebo or control interventions.