Removing the Rust-A Seminar for the Seasonal Runner

David Bernhardt, M.D.Department of Pediatrics, Orthopedics and Rehab

Objectives

• Formulate a plan to start running, improving your fitness

• Understand the possible intrinsic and extrinsic factors which may contribute to overuse injuries

• Guide return to activity if you are injured

Resources

• UW Sports Medicine Clinic 263-8850

• UW Sports Physical Therapy Clinic 263-4765 – Gait analysis– Flexibility– Core strengthening program

Resources

Starting point

• Goals

• Training plan to reach your goal

• Flexible

Training plan• Base – starting point depends on fitness

level

• Core strength– Core Running by Mark Verstegen

• Cross train

• Time to reach your goal

Overuse Injuries

• Common cause of most running injury

• Stress fracture• Tendinitis

Stress fracture

• Tiny cracks in bone

• “march” or “fatigue” fractures

• Bone fracture which usually results from repetitive overload

BONE OVERLOAD• Imbalance between

bone formation and bone destruction

• Osteoblasts: bone matrix formation through production of type 1 collagen, non-collagenous protein and regulatory factors

http://sprojects.mmi.mcgill.ca/bonephysio/index.htm

• Osteoclasts: bone resorption

• Extracellular matrix– Collagen fibers– Ground substance– Inorganic matrix - Ca

and PO4

Mechanical Load Bone Strain

Damage > Remodeling

Stress Reaction

Stress Fracture

Complete Fracture

Mechanical Load

• Weight

• Intrinsic factors – skeletal, muscle, joint, biomechanical factors

Strain

• Change in length per unit of length of a bone

• Repetitive strain usually results in microdamage

• Imbalance of damage and repair leads to stress continuum

Risk of damage

• Magnitude and rate of introduction of the applied load

• Absolute number of loading cycles

Risk Factors• Extrinsic

– Sport– Training – Equipment– Environment

• Intrinsic– Biomechanical

factors– Fitness– Gender

Sprinters – high load, short duration– Foot: metatarsal, tarsal stress fractures

Distance runners – cyclic overload– Proximal stress fractures: tibial, femur

Training Error

• Insufficient time for remodeling or repair

Increase training Increase # of boneremodelling units

Porous bone, Increase strain

Training error• Increase in bone

loading cycles (miles)• Increased intensity

(speed)

• Sports camps• Year-round training

• HOW MUCH IS TOO MUCH?

Equipment

Shoes Inserts

Attenuate load

Kinetic chain

Intrinsic Risk Factors• Fitness

• Biomechanical Factors (Cavus vs planus foot)

• Muscle

• Gender

• Diet: eating disorders, low vitamin D

Pronation

• Limited pronation increases the magnitude of impact loading

• Increases foot flexibility• Attenuates ground reaction impact

forces• Couples with internal rotation of tibia

during first half of stance phase

Menstrual Hx & Bone Health• Extended periods of oligomenorrhea/amenorrhea

may have a residual effect on lumbar BMDDrinkwater B et al. JAMA 1990

Menstrual history & Diet

• SF: older at menarche

• SF: hx of menstrual disturbance

• SF: higher score on EAT-40

• SF: restrictive dieting

Bennell KL Clin J Sports Med 1995

Risk Factors among Young Female CC Runners

• N = 127• 18-26 yo• Stress fracture

confirmed by radiology test

• Baseline BMD, body comp

• Follow-up ave 1.85 y

Kelsey JL, Bachrach LK, et al. MSSE 2007: 39:1457-63

Risk Factor• 891 female Marine recruits• 6.8% with total of 66 stress fractures• Initial 0.86 per 1000 TDE*• Subsequent 3.0 per 1000 TDE

• RF: slowest quartile, secondary amenorrhea

• *training day exposure

Rauh MJ, Macera CA, et al. MSSE 2006

Diagnosis

• Pain localized close to a bone in the lower extremity

• Focal tenderness

Diagnostic tests - xrays• Usually negative in

first 4 weeks

Diagnostic tests - MRI

Sofka CM. Clinics in Sports Medicine 2006

Diagnosis

• Stress reaction: negative xray, positive bone scan with focal tracer uptake

• Stress fracture: positive xray with periosteal rxn

• No clear difference in prognosis

Diagnosis

• Stress reaction: negative xray, periosteal edema, marrow edema

• Stress fracture: negative xray, marrow edema, low signal in the intramedullary bone surrounded by edema

Grading

• I: periosteal edema• II: more severe periosteal edema with

marrow edema on T2 images only• III: moderate to severe edema or

periosteum and marrow on T1 and T2• IV: fracture line present

Fredericson M et al. Am J Sports Med 1995

Prognosis

• I: 2-3 weeks• II: 4-6 weeks• III: 6-9 weeks• IV: cast for 6 weeks and 6 weeks of

non-impact

Fredericson M et al. Am J Sports Med 1995

Prognosis• Fracture line

correlates with longer rest time

Yao L et al. Acad Radiol 1998 (abstract)

Location• Tibial (anterior

tibial*)• Metatarsal• Calcaneal• Tarsonavicular*• Fibular• Femoral• Femoral neck*

• Pelvic – ischial ramus, ischial tuberosity, sacrum

*High-risk stress fxs

High risk

• Risk to progress to complete fracture– Tension side femoral

neck– Anterior cortex,

middle 1/3 tibia– Tarsal navicular

Treatment principles• Rest – activity

modification• Equipment• Immobilization• Weight bearing• Nutritional concerns• Hormonal concerns• Bone stimulator?

• Non-impact exercise– Stairmaster– Elliptical– Water jogging

Treatment

• Correct malalignment• Cross-train• Relative rest• Follow-up q 4 weeks• Allowed to return when non-tender on

examination and no pain with easy running

Return to activity….

• PT consult

• Adaptation

• 5-10% per week rule

Orthotics?

• Orthotic influence differs between running and walking

• Research filled with controversy regarding subject selection, measurement, results, individual foot patterns, kinetic chain

• Success in reducing pain may be more trial and error

References• Bennell K.L., Malcolm S.A., Thomas S.A., et al. The incidence and distribution of stress

fractures in competitive track and field athletes: a twelve-month prospective study. Am J Sports Med 1996; 24 : 211-7.

• Corris EE. Tarsal navicular stress fractures. Am Fam Physician 2003; 67:85-90.

• Heiderscheit B, Hamill J, Tiberio D. A biomechanical perspective: do foot orthoses work? Br J Sports Med 2001; 35:4-5.

• Jones MH. Navicular stress fractures. Clin Sports Med 2006; 25:151-8.

• Kudo P, Dainty K et al. Randomized Placebo-Controlled, Double-Blind Clinical Trial Evaluating the Treatment of Plantar Fasciitis with an Extracorporeal Shockwave Therapy (ESWT) Device: A North American Confirmatory Study. J Orthop Research 2006; 24:115-123.

• Placzek R, Deuretzbacher G, et al. Treatment of Chronic Plantar Fasciitiis with Botulinum Toxin A. Clin J Pain 2006; 22:190-92

• Guten GN. Running Injuries. Saunders Publishing 1997.