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

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

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

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 • Injured during downhill

compared to training

60-70% are soft tissue abrasions, lacerations and contusions • Most common Fx is

the clavicle and dislocation is the AC joint

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 Trauma: Most

Common

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

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 85 –100 rpm equals 499,000 to 588,000 revolutions

Static Bike Fit

Assessment

Bike Fit

Considerations:

• 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

geometry to more acute angle

• Elbow and wrist

- Road 30-50° - Aero 90° - Neutral wrist • Other considerations: - Clothing - Foot-beds - Padded gloves/bar tape - Adjust for individual needs

Bike Fitting

Assessment

• 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 60-120 miles per week. Currently reduced to 20-50 as training for a marathon C/o of left posterior shoulder pain 30 miles into ride

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

- Mid patella tendon over spindle - Seat height for/aft •DBC - Knee angle 25-35° - Seat height for/aft •Seat position - Height of seat - For/aft position - Tilt of seat

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 90-100 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)

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 un-weighting 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

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

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): 271-274. Print.

• .

• Carmont, Michael, R. "Mountain biking injuries: a review." British medical bulletin. 85. (2008): 101-112. Print.

• .

• Christiaans, Henri H.C.M., And angus Bremner. "Comfort on bicycles and the validity of a commercial bicycle fitting system." Applied ergonomics. 29.3 (1998): 201-211. 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. 22.17 (1997): 1965-1969. Print. • .

• Ericson, mats O, and Ake Bratt. "Load moments about the hip and knee joints during ergometer cycling." Scand journal of rehabilitation. 18. (1986): 165-172. Print.

• .

• Fuhrman, Gregg MPT. Cycling biomechanics: evaluation and treatment strategies. WPTA, fall conference, 2009. • .

• Lunardoni, Claire. "How to use cadence and efficiency to ride faster."

Bicycling suite 101sep 10, 2009: 2. Web.07/14/2010. <Http://bicycling.Suite101.Com/article.cfm/pedaling>. • .

References Cont.

aerobic power, and power output on preferred and most economical cycling cadences." Medicine and science in sports exercise. 29.9 (1997): 1225-1232. Print.

• .

• Mellion, Morris B., And . "common cycling injuries, management and prevention." Sports medicine. 11.1 (1991): 52-70. Print. • .

• "Pedaling techniques and drills summary." Beginner triathlete2. Web. 07/14/2010. <Http://beginnertriathlete.Com/cms.Article-details>. • .

• "Perfect pedaling technique." Bikesplit.Com. N.P., N.D. Web. 07/14/2010. <Http://www.bikesplit.Com/bsa4.htm>. • .

• Thompson Matthew J. M.B. Ch.B and Rivara, Federick P. M.D. M.P.H. "Bicycle-related injuries." American family physician. 63.10 (2001): print.

• .

• "Training: the perfect pedal stroke." Bicycling magazine04-30-2010: 2. Web. 07/14/2010. <Http://bicycling.Com/print/943>. • .

• Usabiaga, MD, Jaime, and Ricardo Crespo, MD. "Adaptation of the lumbar spine to different position in bicycle racing." Spine. 17.22 (1997): 1965-1969. Print.

• Questions?