medicine of cycling...19/08/2014 1 medicine of cycling –anatomy of the knee common cycling knee...
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19/08/2014
1
Medicine of Cycling – Anatomy of the Knee
Common Cycling Knee Disorders
Knee Structure
• Hinge joint
• Possesses the largest sesamoidbone in the body- patella
• Caught between 2 multi-axial joints above and below
• The knee moves in 3 dimensional space and must be assessed as such when it comes to quantifying cycling specific patterns of movement
Anterior Knee Pain
• Multifactorial
• Joint- patella tracking:
influenced by bony structure
and mm control.
• Mm length.
• Soft tissue- pat tendon >
quad tendon. (strength v
mechanical advantage)
• Medial Retinaculum/ ligamentous structures
• Medial Patella-femoral Ligament
• Pes Anserine Tendonitis / Bursitis
• Off bike assessment of mm length and strength – functional movement patterns e.g. valgus knee collapse in single leg squat and assess knee tracking through 3D tracking under load
• Plan appropriate distal or proximal control
Medial Knee Pain
Lateral Knee Pain
• Assess muscular system in terms
of mm length and strength.
• Saddle type and stability- both
intrinsic and extrinsic factors.
• Assess accurate biomechanics
when rider is under load.
• Does the rider overextend?
Appropriate for that riders
flexibility.
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• Pes Anserine( more medial but common insertion)
• Biceps Tendonitis(lateral)- assess mm length. On bike look at combination of saddle height and fore/aft-possible rearward position
• Gastrocnemius- proximal calf- can be deep ache- assess pedal technique/ankle drive/ cleat position fore/aft
Posterior Knee Pain
Cycling for Rehab
• low impact rehabilitation tool.
• positive and potentially negative impact.
• The ‘knee’ is the most common lower limb cycling injury.
• Location of symptoms + quantify movement + determining the primary pathology = interventions to an appropriate treatment plan
• Range of Motion- total joint range at hip, knee and foot
• Joint Angles- at different points of the pedal stroke
• Alignments- 3D
• Movement Patterns- how the rider functions as a result of
intrinsic and extrinsic factors
Cycling Kinematics
Determining optimal position on a bicycle while the
individual is riding under a normal physiological load.
What is Dynamic Fit?
Dynamic Fitting Tools
• 2D
• 3D
• Power
Zin Technology
• Digitizes a bike
• Accurate fit coordinates
• Frame geometry
Retül Müve
• Dynamic Fit Bike
Frame Finder Technology
• Frame, Equipment & Fit Database
Retül Fit and Sizing System
Static vs. Dynamic Fit
Static
• Limited joint angles
• KOPS
• No pedal stroke analysis
• No video
• No power
Dynamic
• Full body joint angles and different points of pedal stroke
• Knee forward of foot replaces KOPS
• 3D pedal stroke analysis
• Video
• Power
• Enables a holistic assessment of riders mvt patterns and interaction with the bikes contact points
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Range Of Motion
Road TT
Ankle 23.6 +/- 5.2 24.9 +/- 5.3
Knee 74.3 +/- 3.5 74.1 +/- 3.3
Hip 44.1 +/- 2.7 44.3 +/- 2.5
Variability in Positioning
R² = 0.8738
650
700
750
800
850
900
750 770 790 810 830 850 870 890 910 930 950
SA
DD
LE H
EIG
HT
(M
M)
TOTAL LEG LENGTH (MM)
Saddle height vs Leg Length
Knee Angle Flexion
98
100
102
104
106
108
110
112
114
116
118
KN
EE
AN
GLE
FLE
XIO
N (
DE
GR
EE
S)
Knee angle flexion: road
Road: 111 +/- 2.9°
TT: 111.3 +/- 2.9°
Knee Angle Extension
Road: 36.7 +/- 4.0°
TT: 37.1 +/- 3.6°
25
30
35
40
45
50
KN
EE
AN
GLE
EX
TE
NS
ION
(DE
GR
EE
S)
Knee Angle Extension
Ankle Angle Minimum
Road: 72.6 +/- 6.1°
TT: 68.0 +/- 4.9°
50
55
60
65
70
75
80
85
90
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Ankle angle min
Ankle Angle Maximum
Road: 96.1 +/- 5.3°
TT: 92.4 +/- 4.8°
80
85
90
95
100
105
110
Ankle angle max: road
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Knee Fore/Aft of Foot (Pedal Spindle)
Road: 5.2 +/- 18.2 mm
TT: 77.8 +/- 19.8 mm
-40
-30
-20
-10
0
10
20
30
40
50
60
70
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
KF
F (
MM
)
Knee forward of foot: road
Intrinsic and Extrinsic Factors in Knee
Pain• INTRINSIC
• (Rider Biomechanical Functional Faults and Riding Technique)
• Dysfunctional Joints- Pathology/ ROM/ Instability
• Lack of Appropriate Strength: ‘Robustness’
• Pelvic Asymmetry
• Anatomical Variation e.g. hip retro or ante version
• Pre-fit assessment informs the clinician on the Rider dysfunctional system
• Look for those significant side to side differences
• If bilaterally weak and symptoms are unilateral is the weakness significant
Primary Dysfunctions
Obvious off bike Assessment Movement Faults
• All joints are participating in contributing to lower limb kinematics.
• Altered knee position will occur due to foot orientation in relation to ‘neutral knee’
• Genu Varum v. Valgus-influences patella tracking:
• Must assess the mm system
Intrinsic and Extrinsic Factors in Knee Pain
Intrinsic and Extrinsic Factors in Knee Pain
• EXTRINSIC
• Component choice- saddle too wide/narrow/uncomfortable
• Crank Length **
• The general fit of the bike- self selected of fitted poorly
• Influence of coach on training load prescription/ early season etc
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Knee is caught in the middle….
Proximal
• Saddle shape and
type
• Stability at pelvis
• Mm length and
strength at the hip
• Mm pattern
coordination
Distal
• Bottom up support
• Foot mechanics
• Shoe support
• Shoe type
• Cleat position
Adaptability
MACRO ABSORBERS
Clinical Application
• The same bike fitting interventions affect
different individuals on a spectrum of
effectiveness from productive to damaging
depending on the riders ability to adapt to
change.
• The fit process itself should be dynamic and
open to change.
• Outliers of fit
• Avoid recipe fit procedures.
• Bike is a fixed environmental constraint but is adjustable
• Human is flexible organism but adaptable on a spectrum
Clinical Application
Impact of Changing Position on Kinetic Chain
• Not so simple
• Explains why some people react immediately to changes….. And some resist
• Why some do not change
• Why some change but not has we expected
• Why bike fit for some is important and for others not….
Movement Pathology
Movement Pathology:
• Biomechanical Plotting Often Highlights
Asymmetries
• Frontal Plane
• Transverse Plane
How to Manage the Fit:
• Creating Neutral Position
• Addressing Rider Complaints
• Conducting Mechanical or
Biomechanical Corrections
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Professional vs. Amateur Riders
Novice Riders Can Exert Abnormal Joint &
Muscular Loads – Always Symptomatic?
Summary
• The Knee is the Link in the Chain
• Don’t get side tracked by local symptoms.
• Assess Lower Limb Anatomical Structure and Function and any predisposing factors that may limit a ‘neutral’ fit being achieved.
• Assess individual biomechanical movement patterns to make informed and clinically appropriate fit interventions