9/2/2010. Chronic Musculoskeletal Injuries Experienced by the Cyclist and Basic Bike Fit Solutions: Objectives for Today:

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1 Chronic Musculoskeletal Injuries Experienced by the Cyclist and Basic Bike Fit Solutions: Presented by Pascalle Dumez, P.T. Objectives for Today: Identify frequent injuries, review chronic injuries specific to the cyclist Identify bike fit components Address simple bike fit solutions for chronic injuries Case study Bonus time: consider basic cycle pedal mechanics The Cyclist and the Bike Relationship: Need to consider the cyclist: - Age and health - Experience and skills set - Reason Recreational Fitness Transportation Competitive - Strength and flexibility - Core strength - Current and prior injuries - Pedal stroke - Training style 1

2 The Bike and the Cyclist Relationship: Need to consider the bike - Frame - Seat - Pedals - Shoes - Age of bike - Style Road Mountain bike Cross Time trial Cyclocross Comfort Tandem Bicyclist Injuries: With the increase in cycling for recreational and competitive levels there has been an increase in injuries: Categories of injury: - Acute episode: (macro) Trauma - Chronic: (micro) Bicyclist physical status, conditioning Bike fit Training style, type (overuse) Acute Trauma: Most frequent: - Males - High speed - Collisions Center for disease control states that each year there are more than 500,000 ER visits in the US, and more than 700 deaths as a result of bicycle related injuries 2

3 Acute Injuries: Statistics Males tend to be more severely injured Head and neck injuries from falling over the bike Lower extremity injuries from falling off to the side Females greater incidence over bars due to being lighter 60-70% are soft tissue abrasions, lacerations and contusions Most common Fx is the clavicle and dislocation is the AC joint Injured during downhill compared to training Chronic Trauma Causes Probable causes of repetitive trauma: Intrinsic factors - Anatomical alignment of lower limb - Fitness level - Alterations in kinetic chain, muscle imbalance Extrinsic factors - Frame geometry - Incorrect equipment fit - Training - distance/intensity - Cadence - high/low - Riding/pedal stroke technique Chronic Trauma: Overuse Overuse occurs with damage accumulated in the tissues from sub-maximal loading - Fatigues structure such as bone/tendon Without recovery - Micro trauma stimulates inflammatory response - Release of vaso-active substances, inflammatory cells and enzymes that damage soft tissue Over time leads to clinical injury Results in loss of flexibility, weakness and chronic pain, affects performance 3

4 Chronic Trauma: Most Common Common types of chronic injuries Tendinopathies Joint - Shoulder - Knee - Hip pain Back pain Neck pain Neuralgia - Hand (ulnar and medial nerve palsy) - Foot - Perineum (erectile dysfunction) Saddle sores Knee Pain Knee most common overuse injury in cyclists (40-60% of riders) - Patellofemoral syndrome Increase pressure across PF joint Excessive shear and compression of articular cartilage Poor patella alignment Dysplasia of VMO Tight hamstrings, quad, gastroc Increased Q angle Hyper-pronated forefoot Improper bicycle fit Other Lower Leg Pathologies Other common leg chronic injuries include: - Patella tendonitis - Quadriceps tendonitis - ITB - Trochanteric bursitis - Iliopsoas tendonitis - Medial tibial stress syndrome - Achilles tendonitis - Plantar fasciitis - Parasthesia of the foot - Metatarsalgia 4

5 Cycling Vs. Running Mechanics Cycling - Concentric muscle activation - Relatively non-weight bearing - Propulsion using a machine - 3 areas of contact (5 total points) - Confined ROM Running - Concentric and eccentric - Weight bearing - Propulsion using body - 1 area of contact (2 total) - Minimal limitation of ROM Joint compression forces = run > walk > bicycle Why Bike Fit and Pedal Stroke Mechanics What is the importance of proper mechanics and bike fit? - Reason: cycling repetitive activity, reduce injury In a 60 minute ride at a 90 rpm cadence equals to 5400 revolutions Professional rider e.g. Tour de France: 98 hours over 22 days at rpm equals 499,000 to 588,000 revolutions Bike Geometry 5

6 Static Bike Fit Assessment Bike Fit Considerations: Start at the bottom and work up Cleat position on pedal Knee over pedal (3 o clock) Dead bottom center (DBC) Seat position Trunk angle and spine posture Shoulder angle Elbow and hand position Knee-elbow overlap Stance width Bike Fit Considerations - Norms Trunk angle - Recreational MTB Road Aero 0-20 Shoulder angle - Approx 90 - Changes with bike geometry to more acute angle Elbow and wrist - Road Aero 90 - Neutral wrist Other considerations: - Clothing - Foot-beds - Padded gloves/bar tape - Adjust for individual needs 6

7 Bike Fitting Assessment Male 31y/o, no Hx of injury or current complaints Experience road and triathlete Knee angle at DBC Trunk angle Knee over pedal Shoulder angle Aero Position Aero position is more aerodynamic reducing wind resistance and allows you to generate more power through legs Trunk angle decreases but shoulder angle should remain approx 90. Bike Fit Assessment 32 y/o female riding approx 2 years. Road and triathlon miles per week. Currently reduced to as training for a marathon C/o of left posterior shoulder pain 30 miles into ride 7

8 Continued During fitting unable to adjust cleats, but altered seat aft and slide aeros back This improved trunk angle and knee angle, knee over toes and shoulder angle Plan to ride for a week and come on in to make adjustments to cleats, and readjust bike fit as needed Bike Fitting for Knee Pain Most common causes of knee pain in bike fitting are due to: Increased knee flexion: Poor cleat alignment forward/rotation Low saddle, aft position Increased forces through the knee: Quad biased pedaling Tight hamstring, quad and gastroc/soleus Hyper-pronated foot Low cadence/training style - High resistance (mashing) - Hill repeats Bike Fit Corrections for Knee Pain Cleat position - MTH over pedal spindle - Float in cleat - Toe in/out Knee over pedal - Mid patella tendon over spindle - Seat height for/aft DBC - Knee angle Seat height for/aft Seat position - Height of seat - For/aft position - Tilt of seat 8

9 Case Study 39 year old male Road cyclist for 7 years and MTB for 3 years General health excellent Rides 3-4 per week throughout summer Enjoys other activities including rock and ice climbing, downhill skiing, kayaking Previous soft tissue injury to right leg requiring surgery and right shoulder impingement Reason for bike fitting, occasional hand numbness while riding and feels like he is falling forward into handles Physical examination limitations with gastroc flexibility and thoracic mobility Case Study Baseline Bike Assessment Cleats too far forward on pedal Greater than 40 knee flexion Knee forward over pedal spindle Seat tilted up 40 trunk angle 100 shoulder angle Fully extended elbows Break hoods and handle bar rolled forward Tape on handle bars soft and spongy Rides without gloves (and would prefer to continue to ride without gloves) Rides road bike 2 times per week from baseline rides of HR 140, cadence rpm, distance 25-40, and intensity rides including hill climb repeats Case Study Bike Fitting Changes Adjusted cleat back on shoe Raised seat by 2.5 cm and back approx 0.5 cm, and altered seat to level Rolled handle bars back and adjust break hoods rolling back and slightly in Given calf stretches and thoracic ROM Now: Knee 30, trunk 30, shoulder angle 90, elbows 15-20, good wrist alignment Hands do not go numb (no gloves) States he is faster, new position has improved his ability to produce and transfer power from legs (incl. gluts to and gastroc, to pedal stroke) 9

10 What to Know About Pedaling As cadence increases peak pedal forces decrease As power levels increase, peak pedal forces increase Pedal stroke is not a circle of full constant effort Cyclists do not pull up in the upstroke Body position affects force profiles Body force affects joint moment patterns Pedaling mechanics can be modified Pedal Stroke the Basics: Pedaling in a circle is simple but complex: Zone 1 power phase - 12 to 3 knee extension but focus on hamstrings to get hip extension At 12 toes shoes be 20 point down, at end of zone 1 heel should be neutral or 10 past parallel Zone 2 transition to backstroke - Fire calf muscles to point toe At 6pm toes should be 20 past horizontal to harness energy transfer from zone 1 (ankling, scrapping mud off shoes) Pedal Stroke Continued Zone 3 beginning upstroke (6 to 9 o clock) - Pedal is pushing leg up, goal to use as little power to get leg out of the way by unweighting the foot on the pedal Do not overuse hip flexors to lift foot up Zone 4 end of upstroke (9 to 11 o clock) Think about initiating your down stroke begin as you come to 11pm to push pedal round, not directly down 10

11 Foot Angles During Pedal Stroke At 12 o clock toes pointing down about 20 from the horizontal By time reach 3 o clock toes should be level with ground of 10 degrees of heel past horizontal From here to 6 o clock toes should be pointing down past the horizontal by about 20 As you come back up through the stroke towards 9 o clock un-weighting foot on pedal so angle is setting up ready for going over the pedal at 11 o clock to 12 o clock 11

12 Pedal Stroke Drills Isolated leg drills (ILD) - Spin bike/trainer - Easy gear and unclip one leg - 30 seconds single leg pedal, repeat other leg - Goal to root out dead spots in pedal stroke Focus boxes - Perform after ILD - Goal to transfer awareness to zones of pedaling - Focus on zones i.e: Zone 1 left, zone 1 right, zone 3 left, zone 3 right for 30seconds Reference Carmont, Michael, R, Charles Webb, DO, and Thad Barkdull, MD. "Neck and back pain in bicycling." Current science inc.. 4. (2005): Print. Carmont, Michael, R. "Mountain biking injuries: a review." British medical bulletin. 85. (2008): Print. Christiaans, Henri H.C.M., And angus Bremner. "Comfort on bicycles and the validity of a commercial bicycle fitting system." Applied ergonomics (1998): Print. Crespo, Ricardo M.D., Aramendi, Jose M.D. PhD., Usabiaga, Jaime M.D., PhD. Adaptations of the lumbar spine to different positions in bicycle racing. Spine (1997): Print. Ericson, mats O, and Ake Bratt. "Load moments about the hip and knee joints during ergometer cycling." Scand journal of rehabilitation. 18. (1986): Print. Fuhrman, Gregg MPT. Cycling biomechanics: evaluation and treatment strategies. WPTA, fall conference, Lunardoni, Claire. "How to use cadence and efficiency to ride faster." Bicycling suite 101 sep 10, 2009: 2. Web.07/14/2010. < References Cont. Marsh, Anthony P, and Philip E martin. "Effect of cycling experience, aerobic power, and power output on preferred and most economical cycling cadences." Medicine and science in sports exercise (1997): Print. Mellion, Morris B., And. "common cycling injuries, management and prevention." Sports medicine (1991): Print. "Pedaling techniques and drills summary." Beginner triathlete 2. Web. 07/14/2010. < "Perfect pedaling technique." Bikesplit.Com. N.P., N.D. Web. 07/14/2010. < Thompson Matthew J. M.B. Ch.B and Rivara, Federick P. M.D. M.P.H. "Bicycle-related injuries." American family physician (2001): print. "Training: the perfect pedal stroke." Bicycling magazine : 2. Web. 07/14/2010. < Usabiaga, MD, Jaime, and Ricardo Crespo, MD. "Adaptation of the lumbar spine to different position in bicycle racing." Spine (1997): Print. Wanich, MD, Tony, and Christopher Hodgkins, MD. "Cycling injuries of the lower extremity." Journal of the American academy of Orthopaedic surgeons. 15. (2007): Print. 12

13 Questions? Thank you 13