Strains Flashcards
What are muscle strains?
muscle fibres / tissues fail under imposed demands
common muscles: hamstrings (BF long head), triceps surae (MED gastroc) and quads (rectus femoris)
Muscle strains are not always muscle strain as the muscles damaged are not always in that region
What are the two era’s for grading muscle strains?
Clinical era: used range of signs and symptoms at injury presentation thought to reflect severity of underlying pathology
Modern era: attempts to provide an evidential basis for correlating clinical and radiological grading with injury severity
**increasing grades represent greater severity and longer Rx time
What is a clinical Grade 1 strain?
- localised pain
- small no. of fibres ruptures
- no strength loss
What is a clinical Grade 2 strain?
- pain limited motion
- swelling
- large no. fubres ruptured
- reduced strength
What is a clinical grade 3 strain?
- visual defect
- complete tear
- significant strength loss
BAMIC = Modern Era Grading. What does it mean?
Modern grading of strain:
1. small injuries
2. moderate injuries
3. extensive tears
4. complete tears
a) myofascial
b) musculotendinous
c) intratendinous
Why do tendon strains require longer Rx?
tendons don’t have great blood supply, nutrients and metabolic activity.
What is the difference between Type 1 and Type 2 hamstring strains?
Type 1 commonly caused from high speed running and injury is located at long head of BF-PROX muscle tendon junction. Rehab less than Type 2 but increased RTP if type 1 BF long head intratendinous injury (C grading)
Type 2 caused by stretch-related mechanisms. Injury location is MED hamstring (semimembranosus) and PROX free tendon of semimembranosus near ischial tuberosity insertion. Rehab longer than Type 1
Why is hamstring injury recurrence rate high?
due to scar tissue, atrophy, reduced voluntary activation and reduced hamstring strength
What are muscle strain risk factors?
-previous injury
-sport played
- body position/movement/change of direction
- biarticular anatomy
- structural components (insertion/origin of muscle)
Why does biarticular anatomy influence hamstring strain risk factors?
the muscle crosses multiple joints, stretched out and is under high load/force.
What are the biomechanical muscle strain risk factors for hamstrings?
Hamstrings are vulnerable during the terminal phase of sprinting in eccentric deceleration of the tibia/ control of knee EXT sprinting, hurdling, kicking and jumping
Overall, it is large deceleration with eccentric forces!
List some biomechanical muscle strain risk factors
- Neural activation - mistiming of contractions
- Fibre type proportions - relatively high proportion of fast twitch fibres
- Strength imbalance/deficits - agonist vs antagonist ratio
- Anatomical characteristics - large fascial sheet, intramuscular tendon, long muscle
- Age
