Clinical Trials

Jet Therapy is a product introduced into the South African market some five years ago and involves the application of purified air under pressure to the skin. It is said to be effective in hastening healing of diabetic ulcers, and alleviating symptoms with diabetic feet and in patients with rest pain.

If, as anecdotal reports suggested, it hastens healing of diabetic ulcers, improves peripheral circulation and symptoms in diabetic patients, this needed to be confirmed clinically and the mechanism of action established.

Possible mechanisms are:

The treatment is a form of localised intermittent positive pressure, resulting in the reduction of oedema and improvement of oxygen delivery to dermal cells,
that it induces local vasodilatation and enhancement of peripheral circulation with redistribution from shunt flow to nutritive blood flow in the skin,
that it induces a reflex heating effect with vasodilatation following the period of mild barotrauma and colluding, and
that it is a form of localised hyperbaric oxygen therapy with oxygen diffusion into the skin.

In addition, anecdotal reports obtained from many of the clinics using the Jet Therapy system in various parts of the world indicate that there is a reduction in the appearance of cellulite and body fat in the area that has been treated after a course of 10 Jet Therapy Treatments.

To date, the Department of Physiology at the University of Natal, Nelson Mandela Medical School and the University of Durban-Westville have performed the following scientific evaluations of this treatment, summarised below:

The effect of Jet Therapy on skin blood flow as measured by Laser Doppler Fluxmetry (LDF). This process works by shining light into the skin and sampling all of the moving red blood cells inside the beam. Both LDF skin blood flow and skin temperature were measured before and at various prescribed intervals during treatment.
The effect of Jet Therapy delivered at different air pressures on skin blood flow as measured by Laser Doppler Fluxmetry. As the head of the jet is placed upon the skin, which itself has a massaging effect, this trial was done both with and without air being delivered from the jets.
The effect of Jet Therapy delivered at different air pressures on subcutaneous and intracompartmental muscle pressure using a Stryker intracompartmental Pressure Manometer. This process involved the insertion of a large bore 18-gauge needle under the skin and air pressure being applied over and in the vicinity of the needle.
The effect of Jet Therapy on blood parameters. This was accomplished by means of a Two-Tailed Paired T Test that monitored venous blood before and after Jet Therapy treatment.

1. The acute effect of Jet Therapy on skin blood flow as measured by the Laser Doppler Fluxmetry.

Skin blood flow was measured in healthy volunteers, after 30 and 60 seconds of Jet Therapy using two different applicator heads and unheated air at 1 atmosphere pressure. With the unheated Laser Doppler Fluxmetry probe sited on the dorsum of the foot, treatment at various sites on the foot resulted in a 5-7 fold increases in Laser Doppler derived skin blood flow. Similar results were obtained when the probe was placed on the anterior compartment of the leg. The increase in skin blood flow rate measured appears to decay with distance of treatment from the probe. Significant increases were noted as much as 5 cm away from the measuring site. Skin cooling of about 4c occurred.

With the measuring probes placed on the left foot and treatment performed on the right foot, no increase in skin blood flow inn the left foot was obtained. This would suggest that it is unlikely that the effects of Jet Therapy are centrally mediated or carry over from one side of the body to the other.

2.The effect of 45 minutes of Jet Therapy on skin blood flow as measured by Laser Doppler Fluxmetry.

Skin blood flow and skin temperature was measured in healthy volunteers, before treatment and every 5 minutes during Jet Therapy treatment, at 1 atmosphere pressure, on the footing using the "sport" and "agitator" applicator heads and unheated air. With the probe sited on the dorsum of the foot, the foot was treated continuously for 45 minutes. Measurements were taken during treatment at different sites on the dorsum and medial arch. No readings were taken with the Jet within 5 cms of the Laser Doppler probe. Again, a sustained 5-10 fold increase in skin blood flow was noted throughout the treatment. On cessation of treatment it was noted that skin blood flow rapidly returned to normal values. Skin blood flow and skin temperature was measured every minute for fifteen minutes after the 45 minute treatment of the foot. The skin temperature rose slowly but after 15 minutes was still lower than the pre-treatment value. Skin blood flow, which returned to normal immediately after treatment, did not rise significantly during this period.

3.The effect of Jet Therapy on subcutaneous and intracompartmental muscle pressure.

This study measures the pressure generated by the air jet in subcutaneous fat and in the underlying muscle. Subcutaneous pressure and intracompartmental (ICP) muscle pressures were measured using the Stryker pressure transducer and monitor. An 18 gauge needle was inserted either subcutaneously or into the muscle of the anterior thigh of 10 healthy volunteers. Pressure measurements were made with the air Jet over the ICR needle and repeated with the jet 2, 4, 6, 8 and 10 cm proximal to the needle. Air pressures raging from 0.5 - 4 atmospheres were used in 0.5 atmosphere increments. Substantial increases in both intracompartmental and subcutaneous pressure were recorded, with pressures of up to 8OmmHg recorded at 4 atmospheres. At high applied pressure, the pressure decays within 4 cm of the Jet. The data has not yet been fully analysed. These pressures can result in muscle cell damage, and care should be taken not to treat over a confined area, but rather to move the probe around to reduce the risk. As stated earlier, no evidence of cell damage could be inferred from the blood results.

4.The effects of Jet Therapy on blood parameters.

Two pilot studies have been conducted on a limited number of subjects, to investigate the possibility that Jet Therapy caused muscle cell damage and or damage to blood cells passing the air jet.

Venous blood was drawn from 5 subjects before and after a 'cellulite' treatment, and in a further 5 healthy subjects before and after a 45 minute treatment of the foot. No demonstrable changes were noted in the full and differential blood counts and no morphological changes were noted in the cells. Urea and electrolyte results were all within normal range before and after treatment. There was no increase in creatine kinase or lactate dehydrogenase. While these results indicate that there is no evidence of damage to blood cells or muscle, further work is required to increase the sample size, and to specifically investigate diabetic patients.

In addition, minor studies looked at the following:

The effect of Jet Therapy on blood flow in major arteries and veins.

This study aims to use Duplex Doppler Ultrasound imaging and spectral analysis to quantify changes in blood flow velocity and blood flow volume in major axial arteries and veins when the air jet is applied directly over them. Data on 1 subject suggests that changes do occur. Further work is required.

The effect of Jet Therapy on delayed onset muscle soreness

Delayed onset muscle soreness is used as a model of muscle injury. A project on the effect of Jet Therapy on the resolution of the pain of delayed onset muscle soreness is being planned.

Temperature changes during Jet Therapy Treatment.

The temperature of the air leaving the Jet was measured using the "sport" and "agitator" applicator heads at .5, 1 and 1.5 atmosphere pressure. The temperature of the air entering the compressor is the ambient air temperature. With an external ambient air temperature of 26.3 c and a room temperature averaging 19.75 (+- 0.16c) during the course of taking temperatures of the air leaving the applicator heads, the average Jet air temperature measured 5 cm from the applicator heads was 18.93 c (+-0.28c).

Skin temperature on the dorsum of the foot was measured during 25 treatments of the foot using the "sport" and "agitator" applicator heads at a treatment pressure of 1 atmosphere. Skin temperature was reduced by 4c after 20 minutes of treatment and by 5.05c after 45 minutes of treatment.

The effect of Jet Therapy on muscle pain

This involved a test of pain ratings and "range of movement" readings before and after Jet Therapy treatment in a sample of sportsmen that had just completed a gruelling endurance event over a three-day period. Statistical analysis was performed using the two-tailed Mann- Whitney test.

Conclusion

All the subjects in the sample recorded significant improvements. An associated study of changes in the pain free range of movement following the treatment of muscle pain has not yet been analysed.

Subsequently,

The following studies were done by the Department of Physiology in conjunction with Prof. M.Gregory from the Electron Microscopy unit of the University of Durban Westville.

INCREASES VASODILATION BY UP TO 22%
Previous studies have suggested that massage provides a beneficial effect by local manipulative effects in increasing skin temperature and elevating skin and muscle blood flow. This study investigated the changes in diameters of capillaries in skeletal muscle up to 6 days following deep transverse friction ("DTF") massage as against the Jet Therapy compressed air massage. The data confirmed that massage per se caused a rapid and significant increase in capillary diameters in skeletal muscle. In the case of DTF there was an immediate significant increase of 18% in cross-sectional area reducing to 9% after 24 hours and -7% 6 days later. Jet Therapy caused an initial increase of 13% which rose to 22% after 24 hours and was still evident as a 4% increase after 6 days.
DILATES BLOOD VESSELS FOR UP TO 6 DAYS
The study examined the fine structure and morphometrics of capillaries before and up to 6 days after pure air massage with Jet Therapy. In all cases, both external and lumenal capillary diameters were increased for the duration of the 24-hour test period. It was shown that for any given capillary diameter in control tissue, the endothelial cell thicknesses of capillaries after Jet Therapy treatment is thinner. As it was shown that there was no obvious ultra structural pathology, such thinning is probably a consequence of capillary dilation.
LESS TISSUE DAMAGE
A study was conducted to measure the effect of Jet Therapy compressed air massage on the morphology of untraumatised skeletal muscle. Previous studies have shown that DTF causes a reversible injury characterised by myofibre oedema and subcontraction of myofibres, 2 types of inclusions and other reversible sarcoplasmuic alterations. The morphometric and morphological results of this study suggest that Jet therapy massage, even when applied at high pressure through a single hole 5mm applicator head, appears to cause less and more rapidly reversible damage to the tissues than conventional DTF therapy.

Clinical Trial Diabetic Foot Ulcers

At the present time the fieldwork of a pilot clinical study on the effects of Jet Therapy treatment of diabetic foot ulcers has just been completed at the R.K Khan Hospital Chatsworth, Durban under the supervision of the chief surgeon Mr. Y. Desai and the consulting surgeon, Mr. U.K. Naidoo. The results show that the addition of the Jet Therapy massage to the conventional treatment for foot ulcers provided a reduction of 49.8 days (or 44.1%) in hospital stay.

It is intended to follow-up this study with a second study dealing with neuropathic feet where higher patient numbers will be attainable.

Pictured Left:

RK Khan Hospital in

Chatsworth, Durban

South Africa

Click Here to View Diabetic Ulcer Study in detail

Click here to view before and after pictures of wounds

Please note: View wound pictures at your own discretion due to severity of the wounds.

Clinical Trial Cellulite

A further pilot study is underway to confirm or repudiate the anecdotal claims for cellulite reduction and to establish the reliability of measurement of body fat using three different measuring devices and to establish the mechanism whereby the purported reduction in body measurement is achieved.

Plan Of Investigation

A group of 40 volunteer women, all within the ages of 30-50, are selected to undergo a course of 10 Jet Therapy cellulite removal treatments. The treatments are for one hour at a time, applied every third day by the same operator.

The volunteers are requested to make no material changes to their lifestyles and in a particular their eating habits and their normal exercise patterns.

At the commencement of the study each person will be weighed, and measurements will be taken at a fixed point of both thighs, established by a measurement in height by the subject standing in an upright position, bare footed.

Jet Therapy and...

Clinical Trials

Possible mechanisms are:

1. The acute effect of Jet Therapy on skin blood flow as measured by the Laser Doppler Fluxmetry.

2.The effect of 45 minutes of Jet Therapy on skin blood flow as measured by Laser Doppler Fluxmetry.

3.The effect of Jet Therapy on subcutaneous and intracompartmental muscle pressure.

4.The effects of Jet Therapy on blood parameters.

In addition, minor studies looked at the following:

The effect of Jet Therapy on blood flow in major arteries and veins.

The effect of Jet Therapy on delayed onset muscle soreness

Temperature changes during Jet Therapy Treatment.

The effect of Jet Therapy on muscle pain

Conclusion

Subsequently,

The following studies were done by the Department of Physiology in conjunction with Prof. M.Gregory from the Electron Microscopy unit of the University of Durban Westville.

Clinical Trial Diabetic Foot Ulcers

Clinical Trial Cellulite

Plan Of Investigation

A group of 40 volunteer women, all within the ages of 30-50, are selected to undergo a course of 10 Jet Therapy cellulite removal treatments. The treatments are for one hour at a time, applied every third day by the same operator.