In short, the answer is no. Physiotherapy does not need to be painful to be effective. Unfortunately Physiotherapists have a reputation for providing painful treatments. This is shame as for some people, this may represent a barrier to seeking treatment. I don’t provide the typically “torturous treatments” to my patients because;
it is unnecessary
it might actually impede recovery/rehabilitation
I go to great lengths to explain to every patient I treat that hands on treatment (massage, mobilisation etc) does not need to be painful in order to be effective. I am happy to apply heavier forces if the patient prefers a heavier sense of pressure. But the key is that this is the patient's informed choice.
I don't know how or why it became the norm for Physiotherapists to inflict pain on patients. But it does seem that that it is the norm. I assume it boils down to some sort of misguided application of a "more is better" principle. There's also the fact that many people prefer a hard, perhaps even painful treatment. The important question though is why. Why would a patient prefer painful treatment? Is it because they don't know that there is an alternative? I suspect the answer is yes. But why would a patient think that the only good physio treatment is painful treatment?
I place the blame primarily at the feet of us, the healthcare providers. I think we lead patients on all sorts of therapeutic misadventure when we commence aggressive treatment regimes that aim to "break adhesions" in fascia, "lengthen muscle" or "release knots". Here is the problem. If the Physio is proceeding from an assumption that a patient's symptoms (pain/tightness) is a product of muscle/fascia tightness, it makes sense to do things (stretch, poke, massage) the muscle and fascia so as to reduce the tension, thereby relieving pain, right? But...
The tension in any muscle is dictated entirely by the nerve signals that are sent to it along the motor nerve that attaches to the muscle. For example, if my arm is at rest, my biceps muscle is relatively floppy versus when i am carrying a 5kg weight. When I'm carrying a 5kg weight, my biceps muscle is receiving a steady stream of signals from my musculocutaneous nerve that keep the biceps muscle tense enough to support the 5kg load. It helps to think of any muscle as having a resting or "idling" tension, like a car engine idling away. When we need to up the tension to perform a physical task, the brain decides to up the tension of muscles to support the dynamic requirements of said task.
But what if the task was something more complex than carrying a 5kg object. What if the task was the protection of one of your joints? Let's say you've fallen off a ladder and broken your collarbone. What would your brain do to the muscles in and around the injured areas? Instinctively, you would cradle your arm close to your chest and you would avoid any movement. In other words, your brain would send out steady stream of instructions to your arm muscles saying "don't move, it's not safe".
While the example of a broken collarbone is a little dramatic, I think it helps to think of more run of the mill aches and pains in the same way. Nagging lower back pain for example probably leaves you feeling stiff and rigid. I think it helps to think of your sense of stiffness as a protective bracing of your lower back muscles. I'm sure you wouldn't me as a physio to aggressively crank your arm this way and that in an attempt to reduce the muscle tension that was protecting your broken collarbone, right? So why would you let me go to town and aggressively massage or mobilize the tissues in and around your sore lower back?
When we think of your symptoms as a manifestation of your body's own protective instincts, it allows us to move beyond the "no pain, no gain" treatment philosophy that has been the norm for so long in Physiotherapy. Instead of thinking "we need to get stuck into these knots in order for you to feel better", we can ask the question "what is it that is keeping these muscles in this protective state, and what can we do about it?" We can ask the question "Does it make sense to treat this really aggressively? Could painful treatment actually make this patient's system more sensitive and protective? Might that make their pain worse?"
I prefer to err on the side of not making my patients feel worse than they already do when they walk in the door. Physiotherapy should be about helping a patient's body move from a protective, sensitive, guarded and painful state, to one that is less protective, less sensitive and less guarded. Nearly always this will also result in a reduction in pain and increase in movement freedom.