PRM interventions for muscle, tendon, and other soft-tissue injuries. Functional assessment, therapeutic goals, and development of an individualized rehabilitation program

01How soft tissue heals

Soft-tissue injuries are injuries of muscle, tendon, ligament, fascia, bursa and joint capsule. They come from a single overload (a sprain, a strain, a blow) or from repeated loads the tissue cannot keep up with (overuse). All of them heal the same way, by making new collagen.

1. 1

   Inflammation

   From the first minutes to about 5 to 7 days. Bleeding, then a clot; vessels widen and leak; inflammatory cells clear damaged tissue and release the signals that start repair. Pain, swelling, warmth and loss of function. The tissue has almost no strength.
2. 2

   Proliferation and repair

   From about day 3 to 3 to 6 weeks. Fibroblasts lay down collagen, first the weak type III, and new vessels grow in. The scar fills the gap but is disorganised and fragile.
3. 3

   Remodelling

   From about week 3 to a year or more. Type III collagen is replaced by strong type I; fibres line up along the forces the tissue feels; the scar becomes stronger, but a ligament may stay weaker than before for many months.

Think of the new collagen as wet spaghetti thrown in a pile: if nothing pulls on it, it sets in a tangle; if it is pulled gently in one direction while it sets, it lines up like dry spaghetti in a packet, strong along its length. That is why loading, in the right amount and at the right time, is the main treatment.

Tissues heal at different speeds because of their blood supply: muscle heals fastest, then ligament, then tendon, which is slow and poorly supplied. Cartilage barely heals at all.

02The main injuries

Why injuries happen is part of treating them: sudden increases in training, poor technique or equipment, weak or tight muscles, previous injury (the strongest risk factor for a new one), excess body weight, age-related tissue changes, and certain drugs (fluoroquinolones raise the risk of tendon rupture, especially with corticosteroids and in older people).

03Functional assessment

The assessment asks what is damaged, how badly, and what the patient needs to get back to.

• History: how it happened (mechanism points to the structure), a pop or immediate swelling (suggests a tear or bleeding into a joint), what makes it worse, training load, previous injuries, the patient's sport, job and goals.
• Inspection and palpation: swelling, bruising, a gap in a muscle or tendon, the exact tender spot.
• Range of motion, active and passive, by goniometry.
• Strength by manual muscle testing and, better, by dynamometry, compared with the other side; pain on resisted contraction points to the muscle or tendon.
• Stability tests of ligaments: anterior drawer and talar tilt at the ankle, Lachman and drawer tests and valgus and varus stress at the knee.
• Special tests: Thompson (calf squeeze) for Achilles rupture, painful arc for the shoulder, resisted wrist extension for lateral elbow pain.
• Balance and proprioception: single-leg stance, star excursion test; gait.
• Function: hop tests (single, triple, crossover), the patient's own tasks; questionnaires such as VISA-A (Achilles), VISA-P (patellar tendon), DASH (arm), the lower extremity functional scale.
• Pain: 0 to 10 at rest, with activity, and the next morning, which guides load.
• Imaging only when it changes management: ultrasound for tendon and muscle tears and bursae, MRI for complex injuries, X-ray when a fracture is possible. The Ottawa ankle rules decide on X-ray after an ankle injury: tenderness at the back edge or tip of either malleolus, at the base of the fifth metatarsal or the navicular, or inability to bear weight for four steps.

04Therapeutic goals

Long-term: return to the patient's activities, work and sport, at the previous level, without pain, and with a lower risk of the injury coming back. On the way there, the short-term goals follow the healing phases:

05Building an individualised programme

The first days: PEACE and LOVE

For many years acute soft-tissue injuries were treated with RICE: rest, ice, compression, elevation. Practice has moved on, because complete rest weakens tissue and the evidence for ice is weak. In 2012 POLICE replaced rest with "optimal loading". In 2019 the PEACE and LOVE approach went further:

Progressive loading

After the first days, treatment is mostly exercise, increased step by step:

1. 1

   Protected movement

   Pain-free active range of motion; isometric contractions of the injured muscle at a comfortable effort.
2. 2

   Loading the tissue

   Isotonic exercise against light resistance, through more range; for tendons, slow heavy loading; for muscles, eccentric work added carefully.
3. 3

   Strength and power

   Heavier resistance, then faster movements, plyometrics (jumping, bounding) and running drills.
4. 4

   Neuromuscular control

   Balance and proprioception, from stable to unstable surfaces, single-leg tasks, change of direction.
5. 5

   Sport or work-specific training

   The real movements at increasing speed and intensity.

Progress is set by the response: pain during exercise up to about 5 out of 10 is acceptable for tendinopathy if it settles by the next morning and stiffness is not worse (the pain-monitoring model); swelling or pain the next day means the load was too high, so it is reduced, not stopped.

Muscles, tendons and ligaments

• Muscle strain: a few days of relative rest, then early pain-free movement and loading; eccentric strengthening later (for the hamstrings, the Nordic hamstring exercise, which also halves the rate of new hamstring injuries in prevention programmes). Return to sprinting is gradual, since re-injury rates are high in the first weeks.
• Muscle contusion: protection and compression; no deep massage, heat or forceful stretching in the first days, which increase bleeding and the risk of myositis ossificans.
• Ligament sprain: functional treatment (early weight-bearing with a brace or tape, range and strength exercises, balance training) is better than immobilisation for most ankle sprains. For a severe sprain, a short spell in a below-knee cast or boot for about 10 days speeds early recovery. Balance training afterwards reduces the risk of a recurrent sprain by about a third.
• Tendinopathy: reduce the provoking load, keep the athlete moving, then progressive loading for about 12 weeks: heavy eccentric calf exercises (the Alfredson programme, 3 sets of 15, twice a day) or heavy slow resistance for Achilles and patellar tendons; isometric holds can ease pain. Correct training errors.
• Bursitis: remove the pressure or friction, ice, short-term analgesia; a corticosteroid injection may help non-infected subacromial or trochanteric bursitis. Exclude infection.

06Physical modalities

Modalities make the tissue less painful so it can be loaded. The slides list many; their evidence differs.

07Return to activity and prevention

Return depends on criteria, not just the date:

• full, pain-free range of motion;
• strength at least about 90 per cent of the other side, measured, and the hop tests near the other side;
• sport-specific drills done at full speed without pain;
• psychological readiness: confidence, no fear of re-injury.

The patient goes back gradually, through training, then partial, then full competition or full work duties.

Prevention lowers the risk of the next injury: a structured warm-up with strength and balance work (the FIFA 11+ for football), the Nordic hamstring exercise, balance training after an ankle sprain, sensible increases in training load, good technique and equipment, body weight control, and continuing exercise after discharge.