Table 2.

Outline of the physiotherapeutic procedures.

Stages and weeks after surgery	Programme of basic procedures	Special muscle-strengthening exercises
Stage I 1st–5th week	Ice packs. After several days – local treatment. Passive exercises on a CPM splint with gradual increase in the range of movement of the involved joint. Mobilisation of the patellofemoral joint. Massage of the iliotibial band and the lateral head of the quadriceps. Gait learning and perfection using two crutches. Electrostimulation of the quadriceps and posterior muscles of the thigh. Proprioceptive exercises in a closed kinematic chain. Magnetic field. At the end of Stage I – learning to walk without crutches.	Isometric tension of the quadriceps and flexor muscles of the involved knee joints and other large muscle groups. Isometric exercises with manually dosed resistance of muscle groups beyond the area of the operated knee joint, the uninvolved lower extremity, upper extremities and the trunk. Exercises (on MTD platform): gradually increasing load of the involved leg from 20 to 100% of the body weight. Restrictive two-legged squats on a stable surface.
Stage II 6th–12th week	As above and additionally: Gradual increase in range of movement until a full extension and flexion of the knee joint is obtained. Gait perfection without crutches. Marching on a treadmill, on a flat surface. Initial speed ranged from 2.8 to 3.5 km/h. Desired speed range is from 5.5 to 6.5 km/h. The distance being covered was extended. Exercises on a cycloergometer at the frequency of 60 rpm, without resistance. During the subsequent week – for the first 5 minutes with power of 50 Watt and next, in 10-Watt increments, every 2 minutes. The total time was 10 minutes in increments up to 15 minutes. Every 2 weeks, the initial power value was increased by 5–10 Watt. Walking up and down stairs without crutches. Proprioceptive exercises with assistance on a soft surface: trampoline, mattress, exercise mat and other practice balance beams. Attention focused on preserving a correct Q angle. Marching with changing the inclination angle of the treadmill tape.	Concentric exercises with gradually increased resistance for ischiotibial muscles of the operated leg. Concentric exercises with the physiotherapist’s resistance (this does not apply to the quadriceps of the involved knee joint) of muscle groups of the lower and upper extremities and the trunk. Exercises on a stepper with gradually increased resistance and gradually increased lower extremity range of movement. Squats with both and one leg on an unstable surface. Gradually increased squatting range.
Stage III 13th–20th week	The same as during Stage I and additionally: During the 13th week – measurements of maximal extensor and flexor muscle strength of the operated and uninvolved knee joints on a Biodex 3 System, as the basis for training (see the next column). After obtaining 70% of muscle torque value for the operated legs, as related to unaffected legs, such exercises as running on a treadmill, on a soft surface were introduced, initially at low speed (trot). Next, running on a parquet and on a hard surface. Discipline-specific exercises, initially at low speed; later, the duration of exercises was prolonged and their intensity was gradually increased. Two-legged and next, one-legged jumps on a soft surface, gradually on platforms, then on a parquet and hard surface. Subsequently, the gravity centre shift was placed higher and the degree of difficulty was increased using the unstable surface. Once to twice a week, the exercises were followed by centrifugal massage.	Isometric exercises with partial resistance of the involved knee joint extensor muscles on a Biodex 3 System. The exercises were started with 35% of the maximum torque recorded in the static test. The contraction lasted 5 seconds and was followed by a rest break within the next 5 seconds. The entire cycle was repeated until the patient was no longer able to bear the preset load displayed on the monitor or when the patient reported fatigue threshold or pain threshold. After adaptation to such a load (prolongation of exercise duration with a preset load and fewer errors in bearing the load equal to the value displayed on the monitor), a 40–50% load was applied of the maximum torque during subsequent weeks. After adaptation to these loads, 50–60% and greater loads were applied. From the 16th week of physiotherapy, a strength training was applied in isokinetic conditions at the angular velocity of 180°/s, and next 120°/s. Initially, the knee joint range of movement for extension and flexion of the involved limb was limited to 35–40% of the torque obtained for the preset angular velocity during the control measurement. When the patient increased the number of repetitions and his body adapted to the load in the series for the preset angular velocity, the value threshold for the strength load was increased during exercise performance to 50% and next, to 60% with Mmax and more during consecutive weeks. Exercising was interrupted when the patient could not bear the preset movement velocity any longer during a subsequent repetition or when he reported fatigue or pain threshold. After the patient’s adaptation to the above-mentioned loads during subsequent weeks of Stage III, two series of these exercises were introduced with a 3-minute rest break. At the end of Stage III, the exercises were performed at the full range of movements.
Stage IV 21st week to up to 8 months	As above and additionally: Running with gradually increased speed, then with changing direction and the surface inclination angle. Deep proprioception and neuromuscular coordination were stimulated in the subjects performing discipline-specific or job-specific body movements, using balls, rockets and other sports equipment. Alternatingly, strength, balance, endurance and fitness were restored. Two-legged, one-legged and multi-jumps. Exercises with a skipping rope on different surfaces. Learning obstacle jumping, controlled slides with the physiotherapist’s assistance. Restoration of speed, power, agility and field orientation, specific for a given discipline or the patient’s job. Swimming recommended once a week.	Continuation of strength training – alternatingly – under static and isokinetic conditions. During isokinetic training, speed reduction to 90, and next to 60°/s for extensor and flexor muscles of the operated knees. Concentric-eccentric resistance exercises on devices for large muscle groups. Similar exercises for the muscles affecting involved and uninvolved knees. Exercises in fitness rooms for the remaining muscle groups.