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Elbow stability – is anconeus the driving force?

Val Jones Lead Physiotherapist Sheffield Shoulder & Elbow Unit

The elbow

Incidence

!  6-13 per 100,000

!  Males

!  Chronic instability in 35-40% cases (Eygendaal et al JBJS 2000, Mehloff et al JBJS 1988)

!  Sports related – up to 50 % (Kinter et al JSES 2000)

Presentation

!  Acute

!  Acute on chronic

!  Chronic overload

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Presentation

! PLRI (O’Driscoll et al JBJS 1991)

! Valgus PMRI (Sanchez-Sotelo et al JSES 2005)

! Medial – usually chronic overload

Chronic overload

!  Medial – repetitive over head

!  Usually only on throwing

!  Lateral – crutch walking

!  Affects ADL

Incidence of injuries

!  Baseball 22–26%

!  Rugby 3%

!  Gymnastics 3-8%

!  Tennis 6%

!  Power lifting 6%

!  Snowboarding 2%

Pattern of injuries during throwing

VEO

Shear/torsion Posterior

Compression lateral

Tensile stress Medial

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Forces during throwing

!  Anterior band MCL – 260N

!  Overhead pitch - 300N (MacWilliam et al AJSM 1995)

!  Elbow ext velocity 1300 – 2000 deg/sec (Fleisig et al Sport Biomech 2003, Werner et al JOSPT 1993)

General rehabilitation guidelines

!  Conservative or post-surgery

!  Sequential and progressive

!  Aim is to return athlete to functional level safely and quickly

Presentation

! PLRI (O’Driscoll et al JBJS 1991)

! Valgus PMRI (Sanchez-Sotelo et al JSES 2005)

! Medial – usually chronic overload

General rehabilitation guidelines

!  Conservative or post-surgery

!  Sequential and progressive

!  Aim is to return athlete to functional level safely and quickly

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Phase 1: Early motion

!  Minimise effects of immobilisation !  Prevent elbow flexion contractures

(Protzman et al JBJS 1978, Melhoff et al JBJS 1988)

!  Decrease pain !  Prevent muscle atrophy !  Benefits – articular cartilage and

collagen synthesis (Cyr & Ross JHT 1998)

Elbow range

!  Establish pre-injury baseline

!  Comparing contralateral unreliable

!  Professional asymptomatic throwers – loss of flexion and extension (Wright et al AJSM 2006)

Position for mobilisation

!  Early mobilisation in protected range essential

!  Patient position for exercises and mobilisation techniques is as important as timing

Overhead position

!  Supine overhead !  Shoulder flexed 90 !  Active pronation/

supination !  Active extension !  Progress range as

stability allows

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Benefits of overhead mobilisation

!  Gravity reduces distractional force at UH joint in supine overhead (Lee et al JSES 2013)

!  Gravity in sitting destabilises at all flexion angles

!  Increased in hinged brace

Other benefits of overhead mobilisation

!  EMG activity in stiff or painful v normal elbow (Page et al JHS 2003)

!  Marked increase in biceps activity during flexion & extension

!  Inhibits triceps and limits active range, especially extension

EMG activity in biceps

!  Marked EMG increase in supine or sitting

!  Massive increase activity with weight on forearm

!  DO NOT STRETCH

Phase 1 - muscular rehabilitation

!  Isometrics !  Elbow !  Forearm !  Shoulder –

caution with extremes of rotation

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Elbow stability (O’Driscoll et al 2000) Secondary restraints

!  Medial group – passive stability in supination

!  Lateral group – passive stability in pronation

!  Due to increase in passive tension (Seiber et al JSES 2009, Dunning et al JBJS 2001)

Secondary constraints - activity

!  FPM – generates varus motion reducing load UCL (Lin et al 2007, Park et al 2004)

!  FCU> FDS> PT

!  PT – recruited at high speeds, high load, small effect on stability (Basmjian & Travill 1961)

Secondary restraints

!  Extensor supinator mass !  Produce valgus strain reducing

lateral ligament load (Lin et al JSESJ 2007)

!  Supinator – inefficient force production

!  Continuously active pro/supination !  Activated prior to biceps !  ? Stability and control (Basmajian & Griffin 1972)

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Dynamic restraints

!  Cross joint !  Produce

compressive forces

!  Triceps !  Brachialis !  Anconeus (O’Driscoll et

al 2000)

Anconeus anatomy

!  Elbow extensor

!  15% of total isometric extension torque (Zhang & Nuber 2000)

!  Deep & superficial fibres (Gibbons 2001)

!  Deep – L.E., annular lig, radial collateral lig, olecranon

!  Superficial –L.E., lateral olecranon, posterior ulna

Anconeus – anatomical studies

!  Deep fibres adhere to lateral elbow joint capsule

!  Coapts ulna to humerus, reducing varus instability (Molinier & Lafosse 2011)

!  Exact role unknown

!  ?Lateral stabiliser of the elbow

EMG studies

! Continually active during pro/sup and elbow extension (Basmajian 1972)

!  Activated prior to triceps !  Slow – 60-70% type 1 fibres (Basmajian 1972, Lebozec 1987, Hwang et al 2004)

!  Recruitment important for low load and slow movements (Le Bozec et al 1980)

! Further evidence as stabiliser

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Anconeus

!  Static

!  Locate

!  Multiple points through range extension, pro and supination

!  Low effort, long hold time, no rigidity

!  Clinical evidence as muscular stabiliser

Progression – dynamic range

Phase 1 – kinetic chain (Burkhart, Craig, Kibler Arthroscopy 2003)

Ground, legs, trunk Force generators

Shoulder Funnel Force regulator

Arm Force delivery

It’s my elbow, why are you looking at my legs?

!  50%+ force in tennis serve generated by trunks and legs (McClure et al 2001)

!  Decreased knee flexion in serve increases joint reaction force in elbow

!  Pitchers with UCL tears –reduction in balance on stance and lead leg (Garrison et al JOSPT 2013)

!  Nerve block in triceps reduced pitching speed by only 20% (Roberts 1971)

!  Loss of trunk/ limb control lower control – unstable platform – risk of injury further in the chain

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Compare and contrast Assessment and treatment

!  Single leg balance – pelvic stability

!  Single leg dip – asses pelvic tilt /rotation

!  Y balance test !  Gym ball sitting

Stage 2 rehabilitation

!  Post-op range equals pre-op

!  Minimal pain and tenderness

!  Good power on manual muscle testing

Local strengthening

!  Forearm flexors/extensors

!  Pro/supinators !  GH and scapulothoracic

stabilisers !  Throwers 10 – based

on EMG studies to illicit maximum dynamic stability

!  Increased throwing velocity

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Assessment of shoulder flexibility

!  GIRD (Dines et al AJSM 2009, Endo et al 2013)

!  Internal rotation loss limits follow through, increase pronation

!  MCL strain

Advanced Strengthening – stage 3

!  Progression to prepare athlete for return to sport

!  Increased strength !  Power !  Endurance !  Advanced neuromuscular control

Stage 3

!  Higher resistance, increased speed

!  Eccentric work – biceps –stabilises follow through.

!  Decelerates preventing abuttal of olecranon in fossa

Stage 3

!  Professional throwers – increased FP strength 15-35% (Ellenbecker et al 1997)

!  Increased biceps and triceps 10-20% (Wilk et al JOSPT 1993)

!  Advanced throwers 10 !  Plyometric work – increases throwing

velocity

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Plyometric forearm work Plyometric work

Sport specific kinetic chain work Sport specific kinetic chain

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Stage 4 – interval throwing programme criteria

!  Full pain free motion !  Full strength !  No local tenderness !  Good technique with 1 handed

plyometric throwing !  Good kinetic chain control

Interval throwing

!  Increase distance !  Avoid overload !  Increase intensity

from 50% to 100% in 4-12 weeks

!  Add in different throws – curved ball

Impact work

!  Preparatory muscle activation response in falls

!  Quickens with practice (Burkhart & Andrews 2013)

!  May reduce injury !  Prepares for

contact sport

End stage rehab – the Sheffield way

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Thank you