With a pressure algometer (model Wagner, Wagner Instruments, CT, USA). We will measure pain at pressure, both at the articular level and at a distance (in another part of the body) of patients with hemophilic arthropathy. This device measures in Newton / cm2 the pressure at which the subject perceives pain at the pressure. A pressure will be made on the chosen point, which will increase at an approximate speed of 50 kilopascal / s until the patient warns us that the sensation begins to be painful.

With a pressure hand dynamometer the strength of the brachial biceps, quadriceps and sural triceps muscles will be measured. This device measures in Newton the force that the patient performs in the requested muscular action. The higher the value, the greater the muscular strength. We will perform the measurements bilaterally. In measuring the strength of all the muscles evaluated, the average value of the 4 measurements obtained will be used as a measure.

Using surface electromyography we will evaluate the electrical activity of the musculature and its activation level. The placement of the electrodes will be marked on the standing subjects, and will be placed following the European recommendations for the use of the surface electromyography. A bipolar surface electromyography system with circular electrodes of 10 mm in diameter, 20 mm apart, placed longitudinally, in the direction of the fibers of the studied muscle, and with a remote reference electrode will be used. A baseline measurement will be performed before the intervention and another during the movement visualization in order to measure the change. The unit of measure is microvolts (µV). The higher the score, the greater the muscular activation.

The perception of quality of life of the patients included in the study will be measured with the Short Form 12 questionnaire (SF-12v2). It consists of 12 items and a range of 0 to 100 points (where a higher score indicates a better perception of quality of life).

The anxiety perception of the patients included in the study will be measured with the State-Trait Anxiety Inventory (STAI) questionnaire. The state and anxiety trait of each subject is evaluated with a score of 0 to 30 points for each scale, where a higher score indicates a higher index of anxiety in the trait or state.

We will measure the fear of movement of the patients included in the study with the Tampa Scale of kinesiophobia (TSK-11SV) questionnaire. It consists of 11 items. Their values have a range of 1 to 4 points, where the higher the score, the greater the fear of movement.

We will measure the catastrophism of the patients included in the study with the Pain catastrophizing scale questionnaire. The scale, composed of 13 items, is valued with a range of 0 to 4 points (lower score indicates lower catastrophism).

The anxiety perceived by the patients included in the study at the time of the intervention will be measured with the Subjective Units of Discomfort Scales questionnaire. This scale, graduated from 0 to 100 where 100 indicates the worst anxiety or discomfort lived or imaginable by the subject, consists of anchored scale a 100mm line will be used where the corresponding value will be marked.

The evaluation of the endogenous pain inhibitory system, by facilitating or inhibiting the responses to a conditioned stimulus, will be measured with the Conditioned Pain Modulation Index (CPMI). To perform the evaluation of the diffuse descending inhibitor system, tonic pain will occur by pressing on a non-painful area. First, we will measure the threshold of pain at pressure at the base of the dorsal part of the distal phalanx of the thumb, and then we will cause the conditioned stimulus using the ischemia test on the contralateral upper limb. In this case, for the ischemia test, a sphygmomanometer will be used that will be placed in the arm about 14 cm from the ulnar fossa. The sphygmomanometer will inflate to 240 mmHg and the arm will be placed horizontally.

The joint status of patients with hemophilic arthropathy will be measured with the Hemophilia Joint Health Score. This specific scale for use in patients with hemophilia evaluates 8 items: inflammation and duration, pain, atrophy and muscle strength, crepitations, and loss of flexion and extension. It has a score of 0 (no joint damage) to 20 points (maximum joint damage) per joint (elbows, knees and ankles). To the 120 points a gait rating is added (range 0-4 points), the maximum rating of this scale being 124 points.