Sports Medicine: Just the Facts

Lysholm and Wiklander, 1987). The lower rate of 2.5
per 1000 h is seen in long-distance and marathon run-
ners. Sprinters have the highest rate of 5.8 per 1000 h,
and middle distance runners are between the two at
5.6 per 1000 h (Lysholm and Wiklander, 1987).
•Despite the relatively high incidence rate of running
injuries per runner per year, this incidence rate is still
2 to 6 times lower than in other sports (Epperly, 2001;
Van Mechelen, 1992).

COMMON INJURY SITES

• Most running injuries are musculoskeletal overuse
  syndromes. Seventy to 80% occur from the knee
  down.
  
  
  1. Back 5%
  
  
  2. Hip and groin 15%
  
  
  3. Knee 40%
  
  
  4. Lower leg 20%
  
  
  5. Foot and ankle 20%
     •Top running injuries (Epperly, 2001; Van Mechelen,
  
  
  
  
  
  
  1992. 
        
  
  
  
  

DIAGNOSIS PERCENT

Patellofemoral pain syndrome 32.2
Tibial stress syndrome “shin splints” 17.3
Achilles tendinitis 7.2
Stress fractures 7.2
Plantar fasciitis 6.7
Illiotibial band syndrome 6.3
Patellar tendinitis 5.7
Metatarsal stress syndrome 3.3
Adductor strain 3
Hamstring strain 2.6
Posterior tibial tendinitis 2.6
Ankle sprain 2.4
Peroneus tendinitis 1.9
Illiac apophysitis 1.6

• Although there are no age- or gender-related differ-
  ences, there are differences in injury pattern between
  sprinters, middle-distance runners, and long-distance
  runners. Hamstring strains and tendinitis are more
  commonly seen in sprinters; backache and hip prob-
  lems are more commonly seen in middle distance run-
  ners; and foot problems are more common among
  long-distance and marathon runners (Lysholm and
  Wiklander, 1987).

RISK FACTORS FOR RUNNING INJURIES
(Epperly, 2001)

• Important risk factors (for which a clear association
  with injury has been identified)
  1.Training mi per week (risk increases at 20 mi/week;
  more sharply at 40 mi/week)
  2. Previous running injury (within past 12 months)
  3. Inexperienced runner (running <3 years)
  4. Training intensity (especially with a recent transi-
  tion)


• Equivocal risk factors (for which evidence demon-
  strating a clear link with injury is unclear)

1. Hyper- or hypoflexibility


2. Stretching exercises


3. Running shoes


4. Shoe orthotics


5. Roadside running


6. Malalignment problems

• Unrelated risk factors

1. Age


2. Gender


3. Body morphology


4. Running surface


5. Cross training


6. Time of day


7. Warm-up or cool-down periods

BIOMECHANICS OF RUNNING

THE RUNNING GAIT CYCLE

• During walking, the stance phase occupies 40% of the
  gait cycle. The stance phase is decreased to approxi-
  mately 30% while running and 20% while sprinting
  (Birrer and Buzermanis, 2001).
  •Walking differs from running in that walking has two
  double support periods in stance, whereas running has
  two periods of double float in swing. Running does
  not have a period of double support (Birrer and
  Buzermanis, 2001).

KINEMATICS

• Generally there is an increase in joint range of motion
  as velocity increases; however, there are no major dif-
  ferences between walking and running kinematics in
  the coronal and transverse planes. Most kinematic dif-
  ferences occur in the sagittal plane (Birrer and
  Buzermanis, 2001; Oonpuu, 1990). The body lowers
  its center of gravity (COG) with increased speed by
  increasing flexion at the hips and knees and by
  increased dorsiflexion at the ankle (Birrer and
  Buzermanis, 2001; Mann and Hagy, 1980).


• The hip
  
  
  1. The hip demonstrates an overall increase in range
     of motion(ROM) as velocity increases. The most
     significant motion occurs in the sagittal plane.
     Most of this increase occurs in flexion, as the
  
  
  
  

520 SECTION 6 • SPORTS-SPECIFIC CONSIDERATIONS