Muscle Strain Injuries in Sport

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What are skeletal muscles?
contain protein filaments of actin + myosin that slide past each other to produce contraction and force and motion. Responsible for maintaining and changing posture and locomostion.
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What is a muscle and tendon called?
Musculotendinous unit/junction
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What is a muscle strain?
Overstretching of the muscle which tears the muscle fibres, usually near to muscle-tendon junction as it experiences the highest eccentric load.
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When is a muscle more likely to be pulled?
During eccentric contraction when the muscle is under a linear contraction force but also lengthening
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Describe the 3 grades of a muscle strain?
Grade 1 = some fibres are involved, Grade 2 = significant number of fibres are involved, Grade 3 = Complete tear/rupture
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Give examples of epidemiology of muscle strains?
Most prevalent non-contact injury in football, US football, Aussie football, rugby and sprinting. Cost £74.4 in english premier league clubs during 99-2000 season
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What are the most common strain in football?
Hamstring strain which accounts for 5-7 new injuries per club per season
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When is the hamstring most active?
during running, sprinting which is when they are injured
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When are the quadriceps most active?
Most powerful muscles for straightening the knee for running, kicking and jumping.
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When are hip flexors most active?
muscles at the front of the hip for shooting and striking a ball
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When are the hip adductors most active?
Commonly injuried in football during turning activities and side foot passing
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What percentage of track and field athletes injuries is hamstring strains?
26% of all injuries, usually sprinting events
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What is the reoccurance rate of a hamstring injury?
HIGH! 32% in american football, 27% in aussie rules football, 21% in rugby, 16% in soccer.
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Which hamstring is more commonly strained?
Biceps femoris, with no limb dominance
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What phase is a hamstring strain believed to occur?
The terminal swing phase of the gair cycle because the hamstring is contracting eccentrically (active + lengthening_
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Why is the biceps femoris most commonly injured?
It undergoes the greatest stretch reaching 110% of standing length during running - can be even longer in hurdeling
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What are intrinsic risk factors on a hamstring strain?
Previous hamstring strain, agonist:antagonist strength imbalance (H:Q ratio), lack of flexibility, older age, core stability, muscle weakness, one weaker limb.
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What are possible extrinsic risk factors for a hamstring strain?
Inadequate warm-up, fatigue and dehydration
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What is aponeurosis?
A layer of flat broad tendons connecting the muscle to the bone
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How is aponeurosis believed to be a risk factor?
A disproportionately small biceps femoris long head proximal aponeurosis has been suggested as a risk factor because the mechanical strain are concentrated to a small cross-sectional area.
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What are the signs and symptoms of a hamstring strain?
often happens during sprinting. Sudden limp, forced to stop. Localised stiffness, tightness, descolouration, swelling, redness and bruising. Pain in posterior thigh, sometimes can't weightbear. possible 'pop' sensation. Palpate - muscle belly rupture
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What does broad ecchymosis (discolouration of skin due to bleeding) indicate?
high-grade myotendinous injury or proximal avulsion injury
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What are the 2 tests for a hamstring strain?
Puranen-orava test and bent-knee stretch test
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Describe the Puranen-Orava Test
(Hurdle test) - Patient stands with hip flexed to 90 degrees, knee fully extended, heel on a support (e.g. bench) - increasing posterior thigh pain with extension indicates possible hamstring strain
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Describe the Bent-Knee Stretch Test
Patient lie supine on bed, hip and knee maximally flexed. Patient relaxes and examiner slowly + passively extends the knee. Pain in posterior thigh indicates hamstring strain
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When is an x-ray helpful?
not helpful for strain unless an avulsion fracture has occurd from ischial tuberosity
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What can a Dynamic ultrasonography show?
fluid collections around the injured muscle, which represent edema and/or hemorrhage.
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What can an Magnetic Resonance Imaging (MRI) show?
Can help define the injury location, degree of damage, number of involved tendons, extend of retraction and chronicity
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How is knee strength defined?
knee strength is maximum torques generated by hamstrings and quadriceps
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What test can assess knee strength and how?
Isokinetic dynamometer test = flexion and extension speed fixed. Resistance depends on torque generated by participant. Safe assessment!
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What 4 relationships could be used in the isokinetic dynamometer test?
1 - concentric hamstring to concentric quad (conventional ratio), 2 - Eccentric hamstrinc concentric quad (functional H/Q ratio), 3 - Concentric hamstring eccentric quad, 4 - eccentric hamstring to eccentric quad
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Which relationship is most often used in the test?
Functional H/Q ratio is often used to represent the knee/hamstring strength as the hamstring is usually lengthened when working.
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What are the NHS management guidelines?
RICE: rest (no running or jumping), ice (20 minutes 3 times a day), compression, elevation. Followed by stretches and strengthening exercises.
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What stretches are useful for hamstring recovery?
Lie on your back, raise leg, pulling it towards body. Hold 10-15 seconds. Also - buttock stretch when lieing on back one leg crossed over the other.
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Give examples of strengthening exercises
Supine bent knee bridge walkouts, supine single leg chair bridge, single-limb balance windmill touches with dumbbells
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How do you treat a complete hamstring tear?
If its torn in 2 parts, surgical operation needed.
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What are the 4 stages of a hamstring surgery?
Patient prone on operating table, transverse incision made in gluteal crease inerior to ischial tuberosity, hamstring tendon secured to bone, braced with hip orthotic in 30-40 degrees of flexion to limit stress to surgery site
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What happens in the first 6 weeks of rehab from surgery?
Asprin prescribed for 4 weeks to avoid DVT, day 10-14 toe-touch weight-bearing with crutches, weeks 2-5 25% weight bearing with hip orthotic. Therapist to help ROM and passive exercise at 2 weeks. 4 weeks active exercise.
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What happens between week 6 and week 16 of rehab?
Week 6 - hip orthotic removed, full weightbearing. Gait training. Week 8 - dynamic training and isometric strengthening, week 10 - strength evaluation with knee at 60 degrees, week 12 - sport-specific training, week 16 - full isokinetic evaluation
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When can the patient return to full sport following hamstring surgery?
Full sport is allowed when operative leg is 80% of the non-operative leg on isokinetic testing. 6-10 months post-surgery usually
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Name a useful guide for prevention of hamstring strains?
The FIFA came up with the 'FIFA 11+ warm-up programme including nordic hamstring exercises.
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Other cards in this set

Card 2

Front

What is a muscle and tendon called?

Back

Musculotendinous unit/junction

Card 3

Front

What is a muscle strain?

Back

Preview of the front of card 3

Card 4

Front

When is a muscle more likely to be pulled?

Back

Preview of the front of card 4

Card 5

Front

Describe the 3 grades of a muscle strain?

Back

Preview of the front of card 5
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