This is one of the questions commonly being asked by clients at work. Different therapists may have different opinions but the opinion stated below is purely mine.  I’m not going to go technical.  I just want everybody to understand, no matter what background you are, or education you had.

Both techniques target the Trigger Point, for the same reason – to relief pain and tension.  One is a hands-on work requires only to work over the skin, and the other with a small filament needle (same type as acupuncture needle) that requires to insert and penetrate through the skin.   Both are effective, but only "situational-ly" effective. 

With the hands on work, how much the client can benefit from the technique will depends on the level of their pain tolerance, how they breath, the level how much they guarding the muscle while getting treated in that specific area, and the level how much they can relax the muscle (Guarding muscles and relaxing the muscle in this context are very different, one is consciously tensing up muscle to protect oneself, and the other is involuntarily contraction that they don’t even know they are not relaxing.), and of course how well they comply with the recommended self-care program;  As it was said, it is performed over the skin, so the pressure required will be different according to the depth of the targeted muscle’s location and to the intensity level of tension built up in that trigger point.  Therefore, the deeper the muscle is targeted, the deeper my pressure needs to go, which also giving the client a misinterpretation of that “I’m going hard”.  Also, the more tension is accumulated inside the trigger point, the more sensitive client feels when pressure is applied.

On the other hand, Dry Needling, sounds invasive, but it is specific and can efficiently release tension quicker than manual work. Needles come in different length to target muscle in different depth easily.  So this technique is always preferable for me when treating client with thicker muscle mass.  Not like the manual work which require the “elbow” to go harder in order to go deeper.  However, the person who receives the treatment also needs to be at ease with the needle for the treatment to be effective.

So, for me, they both have pros and cons, depends on situations. Some situations are better with Dry Needling, some situations could be enough by using Trigger Point therapy, some situations may have taken too long to release with trigger point therapy then I will consider switching to needles. So no matter what situation, my main concern will always be how my client feels at time on my treatment table.  Are they too sensitive to be touched? are they fear of needle? do they have faith on the needling technique? or do they have faith in me not?  If anything of these questions checked, then I will just stick with the use of my hands.