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Pointing light at musculoskeletal and neurological conditions: clinical applications 107
hips, and stifles treated, clipping is not likely to be an
option, and although preferable, is not indispensable in
most cases.
The exceptions to treating in contact would be
recent fractures or conditions with concurrent skin
damage. If the animal is in pain when touched, contact
can be avoided during the first sessions at least; to avoid
losing power density (which can be significant for pain
management and crucial to achieve significant penetra-
tion) you will need a hand-piece with an adjustable spot
size, or an extra hand-piece with a smaller tip, able to
concentrate the beam from a distance.
9.1.1 Dose (J/cm )
2
The range of appropriate doses or energy densities for
most cases will be from 4 to 15 J/cm (Table 9.1), and as
2
in the soft-tissue applications described in Chapter 7,
this will vary according to the following factors.
• The depth of the condition: a calcaneus tendon is
quite a superficial target, especially if we compare
it with an iliopsoas or the caudal cervical muscles.
Remember that most of the dose will be absorbed
in the more superficial tissues, but a higher starting
dose still means more energy will be left at a certain
depth.
• The chronicity of the process: chronic conditions
Figure 9.1 Treating in contact and with a degree of pressure need about a 30–50% higher starting dose. So after
that is comfortable to the patient improves penetration of an acute trauma to the hip area, the initial dose will
light. Remember to keep the hand-piece perpendicular to the be about 5–6 J/cm , but a chronic osteoarthritis will
2
surface. require around 8–10 J/cm to begin with.
2
• The amount of inflammation present: managing
• While applying pressure we decrease the distance inflammation may need a lower dose than treat-
from the probe to the depth of tissue. ing pain. What is more important is that whatever
• By mobilizing the vascular bed we push away blood, dose you choose should not be delivered with a high
therefore it will absorb less energy and allow more power density. [37]
photons to travel deeper, so we improve penetration.
• If the tip of the probe is being held and surrounded It makes sense to treat an area that is proximal to
by your hand (Fig. 9.1), contact also lets you know if the injury, not just for the blood flow – although this
there are tender, fibrotic, or other abnormal areas, will be improved if there is a lack of it – but for the
and gives real-time feedback about the surface segmental analgesia. In painful conditions, especially
temperature. in chronic ones, the nerve roots supplying that area
may be sensitized. Consider the associated spinal seg-
The non-dominant hand can help separate the coat, ments as extra treatment areas if necessary, especially
which will also improve penetration, although not as in chronic and refractory pain. For instance, consider
much as the alternative of shaving/clipping the area. In treating the lumbar area together with the knee area
practice, clipping is possible if only one or two areas if a case with chronic osteoarthritis of the stifle is not
are affected; but if the patient needs to have the spine, improving. These extra treatment areas need to have
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