1. Paul Thawley MSc, BSc (Hons), PgDip (Rehab), MCSP SRP Senior Sports Physiotherapist Team GB
Hamstring Injuries

2. “Hamstring injuries occur in all sports and effect elite and non elite populations” (Brooks et al 2006)

3. Athletic Population

4. Non Athletic population

5. Epidemiology
FA Audit of Injuries study found that 12% of all injuries reported over two seasons were hamstring strains. (Woods Br J Sports Med 2004;38;36-41)
11-15% Cricket (Stretch 2003, Orchard et al 2002a)
16% AFL with a recurrence rate of 34% Seward et al (1993)
Incidence 0.30 per 1000 playing hours with average severity of 17 days absent in English Rugby Union – Brooks et al (2005)

6. Epidemiology
Epidemiological evidence suggests that hamstring strains are associated with eccentric load, where the contracting muscle is lengthened and there may well be a lack of neuromuscular control.
Biggest risk of injury is previous injury
Biceps femoris most commonly injured
Increased incidence with age

7. Posterior Thigh Pain: Differential Diagnosis
Hamstring muscle strain; Acute / Chronic Hamstring muscle contusion Referred from Lx Neural structures; Triggers points

8. Less Common Posterior thigh pain
Referred from SIJ
Tendinopathy
Bursitis
Compartment syndrome
Apophysitis
Nerve entrapment
Adductor magnus
Myositis Ossificans

9. Not to be missed
Tumors
Iliac artery insufficiency

10. Diagnosis
Listen Hx is key
Look
Move
Feel
Special tests

11. Neural Dynamics
Slump test as a diagnostic tool Slump as a treatment modality Significant effect on Fascia – Vleeming et al 2005
The slump test is said to significantly differentiate referred posterior thigh pain from that due to muscular-tendon strain [13] and has been able to identify those with recurrent hamstring strains in a small study [14]. Slump stretching as a treatment procedure (when slump testing is positive) has been shown to be more beneficial in returning athletes to competition than standard physiotherapy treatment alone (ultrasound, massage, progressive flexibility and strengthening) [13]. The slump test has been proposed to be a measure of 'neural tension' which is postulated to predispose hamstring injury [14]. However, the anatomical relationship of the hamstrings with the thoracolumbar fascia (TLF) system has been neglected. The tendon of bicep femoris is continuous with the sacrotuberous ligament, passing across the sacrum and attaching to the thoracolumbar TLF [16]. This functionally connects the hamstrings to the lumbar spine, upper torso, shoulder and occiput and casts doubt on reliability of the slump test as being able to measure neural tension [17]. Contracture of the muscular attachments of the TLF has been documented to cause TLF its displacement [16]. Therefore neural tension may only be an assumption and it may more likely be myo-fascial tension, or possibly a combination of the two giving a positive slump test. Postural changes such as forward weight bearing, as occurs during forward lean gait, will also cause hamstring tension and predispose hamstring injury. This suggests that the TLF system should be assessed during treatment of hamstring injuries.

12. Lumbar Spine
Age / Degeneration of L4/5 and L5/S1 associated with prevalence of hamstring injuries Successful management of hamstring injuries in Australian Rules footballers: two case reports Chiropractic & Osteopathy 2005, 13:4 doi: /
Australian Rules footballers with a previous back injury have been found to have a significant increased risk of hamstring injury [9]. A strong relationship between age and hamstring, calf and Achilles injuries (with a L5 and S1 nerve supply) also exists in AFL players [18]. The L4/5 and L5/S1 levels are the most common areas for spinal degeneration and athletes are susceptible to degenerative changes at an earlier age than the normal population [19]. Altered neural input from the levels that innervate hamstrings may be causing and prolonging hamstring injuries. Long term prospective studies are required to further investigate this finding.

13. If your think the lesion is soft tissue Dynamic Ultrasound or MRI are you investigations of choice

14. Common mechanism Late swing phase in running action
Eccentric contraction to decelerate the shank
Often accentuated in preparation to jump, kick
Trunk flexion whilst running (Verral, 2005)

15. Other mechanisms
Stretch with knee fully extended (stretching for a ball, kicking)
Forced trunk flexion with foot planted (waterskiing)

16. Possible causes of Muscle Injury
Musculoskeletal imbalances
Poor muscular co-ordination
Inappropriate training
Fatigue
Incomplete rehabilitation

Repeated micro-trauma


17. Intrinsic and extrinsic factors
Musculoskeletal imbalances
Any breakdown in the effective function of the legs and pelvis during running may predispose to injury. Examples include:
postural changes due to muscle tightness
lumbar or sacro-iliac joint stiffness
poor co-ordination of movement or early fatigue associated with muscle weakness
leg length discrepancy (LLD) which will affect pelvic motion and stride length. Note: LLD < 1.5 cm is usually not significant
prolonged or delayed pronation or supination of the foot, which will alter the function of the leg and pelvis during the running cycle

18. Intrinsic and extrinsic factors
Poor muscular co-ordination

Running requires strength, power, endurance and co-ordination. Problem-free running cannot take place if the hamstrings are weak, inflexible, or if there is poor neuromuscular co-ordination. Loss of the normal ratio of muscle power between the quadriceps and hamstrings may also occur. The normal quadriceps/hamstrings ratio is 60:40. Loss of the normal ratio may be due to excessive development of the quadriceps, or due to existing weakness of the hamstrings. A normal ratio is essential to prevent imbalances from occurring during the running cycle.

19. Inappropriate training
“Inappropriate” comprises all the factors that may affect your body’s ability to adapt to the varied stresses of running. Factors include:
excessive mileage
rapid increase in mileage
inadequate warm-up and cool-down
poor stretching
cambered running surfaces
worn shoes or orthotics

20. Fatigue

Fatigue affects performance and may predispose you to injury. At a physiological level, fatigue may be reflected in a prolonged recovery time at neuromuscular junctions, which diminishes effective muscle activation, slows the clearing of metabolites from the muscle, and impairs the ability of the muscle to contract. Fatigue therefore results in decreased strength, power and endurance, and will increase the risk of injury.

21. Incomplete rehabilitation
As runners, we are always eager to get back on the road as soon as possible. If an injury is not properly treated, or if you do not achieve your pre-injury levels of strength, endurance and flexibility, the risk of re-injury is increased. Effective rehabilitation (which means putting in the time with the physio, or at the gym) will allow you to get back on the road and stay there.

22. Repeated micro-trauma
Often trauma to the hamstrings may not always be significant enough to cause pain or disability at the time of injury.The reduction in hamstring function may be so gradual that it will not be detected until there is a serious problem. This is often described as “the last straw that broke the camel’s back”, where repeated micro-trauma will finally result in pain and dysfunction. When running, the hamstrings are often exposed to repeated micro-trauma due to over-striding, as well as with a change of pace. Over-striding, particularly when just starting to run downhill, places the hamstrings under excessive eccentric load as the muscle works to stabilise the knee joint. The excessive eccentric load may result in micro-trauma to the muscle fibres, leading to injury.

23. Treatment approaches

24. Muscle Injury
What are the consequences to the athlete of not treating a muscle injury correctly?
How much damage is caused by inactivity on the athletes and the doctors part?
Why is there no/little consensus on management of muscle injury?

25. Staring point with an Hamstring lesion
R.I.C.E Compression the key Gentle mobilisation Partial weight bearing as tolerated Electrotherapy modalities When to stretch? When to start running again?

26. Continued Rx STR / MFR Acupuncture NSAIDs after 24 hours
Electrotherapy modalities
Correct Physical rehabilitation is paramount in the management of hamstring injuries

27. Early mobilisation versus strength/stretching
Two rehabilitation programs
Static stretching and progressive strengthening
Progressive agility and lumber stabilisation program
No stat difference in RTS times
Stat difference in recurrence rates over I year period remain ISQ (Sherry et al, JOSPT, 34(3): )

28. Where basic science and clinical guidelines collide
Perception is that early mobilisation is against basic principles.
RICE principle for 7 days minimises pain, swelling to offer best possible conditions for healing process. Kannus et all (2003)
Studies cited were for non-contractile tissues (ie ligaments)
Prolonged immobilisation is detrimental
Early mobilisation of affected tissue increases density of scar formation. (Jarvinen, 1975) What about remodelling???

29. Accelerated running program
                         
Developed by Graham Reid
Australian Hockey Physio
Injured player on tour
Captive audience
Good result

30. Accelerated Running Program
Day 0:
Ice, Electro modalities, +/- CPM, +/-Ice, Compression etc
Day 1:
Continue as above.
When range in sitting position (Lordotic spine) at 120 or - 10 degrees off full knee extension ? start running program

31. Progressive Running Program Graham Reid
Jogging at variable speed up to 75%
Minimal acceleration/deceleration
Approx 4 min/km pace
Up to 2 kms
Variable distances 100mx3, 90mx3, 80mx3, 70mx3, 60mx3, 50mx3, 40mx3, 30mx3: Repeat x 2
Backwards running: 50 x 3 , 75 x 6, 40 x 3

32. Progressive Running Program Graham Reid
Once at 75% without pain, start acceleration program
40 – 20 –40
–35

33. Summary of running program
Aggressive but controlled rehab
Takes out a lot of the guess work with training loads
Many variations – needs to be tailored to the sport and then the individual athlete
Addressing causative factors is the most important aspect to hamstring rehabilitation

34. My approach to pre running criteria
(how do you know when the athlete can run ????)
Adductor magnus bridges 5 sets of 12 reps
Seated knee extension = 10 degrees off straight
Single leg long level bridge = pain free

35. Hamstring Exercises
Manual resistance
Manual therapy

36. Rehabilitation approach

37. Why does early mobilisation work?
Eccentric exercise in a controlled way is functional
Improved neural patterning/technical ability
Allows progression as quickly as possible with consistent feedback
CPM effect- decreases disorganised collagen formation. Maintain extensibility of the muscle
Hamstring strains are almost never isolated strains
Strengthening in a functional way

38. Recurrences Scar at its weakest point 10-12 days after injury
Time frames will vary - forced by time constraints
Analogous to ACL return at 6 months

39. Injury prevention Extremely difficult! The
hamstring strains occurring in sprinters during maximal
the sprinter’s
strain involving primarily muscular tissue, and the dancer’s
strain more proximal tendinous tissue.
speed running caused a more striking acute decline in
function, but had a faster recovery time than those occurringin extreme positions during stretching exercises in dancers.
Interestingly, there were no correlations between time to
return to pre-injury level and the magnitude of the acute loss
or short term recovery of hip flexibility or knee flexion
strength.
The injury seems to be
related to the magnitude of force, rate of force development,
and/or length change rather than extreme joint positions.13

40. Eccentrics??? Concentric Eccentric
Characteristics of eccentric contraction
Produces more force than concentrics
Selectively recruits Fast fibers. Fast fibers are bigger and have greater potential for growth than slow fibers.
During the eccentric phase of movement, the muscle absorbs energy. This work is done “by stretching the muscle and in this process the muscle absorbs mechanical stress This mechanical energy is dissipated or converted into one or a combination of two energies.
1. Heat
2. Elastic Recoil

41. Key concepts in injury prevention
Improve the training regime so that it more accurately reflects sports specific conditions with the goal of improving muscle conditioning;
Try and improve fatigue resistance of the hamstring muscle
Try and induce a change in the viscoelastic properties of muscle so as to increase energy absorption and decrease load on the muscle-tendon unit for any given length especially in body positions of function and vulnerability to injury. Verrall et al 2005 Br J Sports Med

42. Can we predict/prevent hamstring strains?
Previously injured muscles developed peak torque at significantly shorter range than uninjured muscles Peak torque and quad / hamstring torque ratios were not significantly different Eccentric exercise possibly shifts length-tension curve to the right Most Studies used concentric measurements, Why when we know hamstrings have an eccentric action? (Brockett et al, 2004: Med Sci Sports & Ex. 36(3))

43. Predicting/ Preventing muscle strains
Role of screening
Hamstring range
Strength components (Isokinetic)
Joint ranges
Traditionally, our biggest predictive factor to hamstring strains is previous history of hamstring strain.

44. Can we predict/prevent hamstring strains?
Decreased incidence in soccer players on an eccentric program
Askling et al (2003): Scand. J. Med. Sci. Sports 13:
Decreased hours lost, no of injury and weeks out with intervention program (Verral, BJSM 2005)

45. Incremental Increase in Eccentric Exercise
Drop-catch exercises (Stanton and Purdam 1989 J Orthop Sports Phys Ther) Nordic hamstrings High-velocity eccentric exercises in the final phase of rehabilitation (Geraci 1998)
Stanton and Purdam6 describe
“drop-catch” exercises in the prone position with the hip
in flexion or with the athlete lying over the edge of a
table. Quick active knee extension is followed by rapid
deceleration via hamstring eccentric contraction, followed
by rapid concentric contraction. The athlete progresses
from slow catches to faster velocities over several
training sessions. Light weights can be added to the
ankle with the athlete returning to slower catches with
each higher weight before progressing to faster catches.

46. Hamstring Exercises
Nordic Hamstrings

47. Icelandic curls
research From: Bahr and Meahlum (2002)

48. Length-tension relationship

49. Icelandic curls
Tension

50. Points to consider in Footballers
Body awareness
Requirements of the Sport
Limited neural aspects
Limited kicking etc. till full running
Ball work restricted in initial stages
Physical rehabilitation does not replace intensive hands-on approach
How to integrated this philosophy with the football management

51. Sports Specificity relating to hamstring injury prevention
Think specific and generic
ie Football
Ladders
Change of direction
Backwards/sideways running
Shuttles
Chase and escape drills
Recreate load, stress, strain, joint angles, fatigue index

52. Case Study Primary hamstring lesion grade 1+ on US Day 1
PRICE crutches 2/7 no NSAIDs
Day 3
STR / PNF local electrotherapy + NSAIDs
Seated SLR / passive mobilisations
Day 5 program
Active mobilisations / basic gym program
Day 7
Hamstring specific program (powerpoint)

53. Re US scan good reduction in fluid RTP day 18 Post injury
Case Study Contd
Day 14
Re US scan good reduction in fluid
RTP day 18
Post injury
S&C lead eccentric program in place and a physio lead pelvic neuromuscular patterning program with monitoring

54. Summary Diagnosis is key, use correct imaging modalities
Initial treatment is in line with any other soft tissue injury; protection, RICE and early mobilisation.
Understand that there is close relationship between hamstring injury, the neural system and lumbar spine pathology

55. Apply an eccentric injury prevention strategy
Summary continued
Accelerated running programs can be utilised
Identify predisposing factors relating to the hamstring injury in that individual athlete
Apply an eccentric injury prevention strategy
Develop your own strategy related to current research evidence
Be sports specific in your approach

56. Questions/comments/discussion?

57. References
Kyro ̈ la ̈ inen H, Komi PV, Belli A. Changes in muscle activity patterns and kinetics with increasing running speed. J Strength Cond Res 1999;13:400–6.
Pinniger GJ, Steele JR, Groeller H. Does fatigue induced by repeated dynamic efforts affect hamstring muscle function? Med Sci Sports Exerc 2000;32:647–53.
Garrett WE. Muscle strain injuries: clinical and basic aspects. Med Sci Sports Exerc 1990;22:436–43.
Best TM. Soft-tissue injuries and muscle tears. Clin Sports Med 1997;16:419–34.
Stauber WT, Knack KK, Miller GR, et al. Fibrosis and intercellular collagen connections from four weeks of muscle strains. Muscle Nerve 1996;19:423–30.
Stauber WT, Smith CA, Miller GR, et al. Recovery from 6 weeks of repeated strain injury to rat soleus muscles. Muscle

58. References
Askling C, Saartok T, Thorstensson A. Type of acute hamstring strain affects flexibility strength and time back to pre-injury level. Br J Sports Med. 2006;40:40-44.
Askling C, Tengvar M, Saartok T, Thorstensson A. Sports related hamstring strains—two cases with different etiologies and injury sites. Scand J Med Sci Sports. 2000;10:
Brooks JHM, Fuller CW, Kemp SPT, Reddin DB. Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union. Am J Sports Med. 2006;34:
Connell DA, Schneider-Kolsky ME, Hoving JL, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol. 2004;183:
De Smet A, Best T. MR imaging of the distribution and location of acute hamstring injuries in athletes. AJR Am J Roentgenol. 2000;174:
Gabbe BJ, Bennell KL, Finch CF, Wajswelner H, Orchard JW. Predictors of hamstring injury at the elite level of Australian football. Scand J Med Sci Sports. 2006;16:7-13.
Garrett WE, Rich FR, Nikolaou PK, Vogler JB III. Computed tomography of hamstring muscle strains. Med Sci Sports Exerc. 1989;21:
Gibbs NJ, Cross TM, Cameron M, Houang MT. The accuracy of MRI in predicting recovery and recurrence of acute grade one hamstring muscle strains within the same season in Australian Rules football players. J Sci Med Sport. 2004;7: