ASCA conference 2011 - Overhead Pressing

Australian Strength & Conditioning Conference 2011

Dr Mark McKean Fitness Research 1

Dr Mark McKean PhD AEP CSCS

OVERHEAD PRESSING – EFFECT ON

SHOULDER GIRDLE AND SPINE

WHAT YOU WILL LEARN

Evolution of shoulder posture

Research aims

Methods

Results

Conclusion

Application

EVOLUTION OF SHOULDER

POSTURE

EVOLUTION OF THE SHOULDER

The feature that has received the most attention in functional analyses of fossils is the orientation of the glenoid fossa.

In hominoid primates the glenoid faces cranially reflecting the importance of overhead limb postures, while in modern humans the fossa faces more laterally reflecting the typical lowered position of the upper limb.

X-rays showing glenoid-spine

angle of the scapulae of

a) a modern human,

b) KSD-VP-1/1,

c) a gorilla, and

d) chimpanzee.

Researchers suggest that either 1) the shoulder blades

underwent significant modification once hominids started walking on the ground, or

2) 2) that they represent a unique mode of locomotion unlike any seen among the few living hominids.

From Haile-Selassie et al,

2010.

http://education.yahoo.com/reference/gray/subjects/subject?id=50#i205

http://education.yahoo.com/reference/gray/subjects/subject?id=50#i205



NEANDERTHAL

Scapula have high spines and the acromion is farther away from the axis of rotation (Trinkaus 1983).

Mediolaterally they are wider (Debenath and Tournepiche 1992).

Thus Neanderthals were probably better at throwing (Debenath and Tournepiche 1992) than their modern contemporaries. This would make them better thrusters and could relate to hunting techniques and tool knapping.

SCAPULA VARIATION

Cursorial (running) mammals usually equipped with longer, more narrow scapulae which is positioned more vertically compared to ambulatory (unspecialized) mammals.

Fossorial (digging) and natatorial (swimming) mammals equipped with triangular scapulae and larger teres process.

Provides greater leverage from teres major muscle resulting in more powerful adduction of forelimb.

GLENOID FOSSA ORIENTATION

CHANGES WITH POSTURE

RESEARCH AIMS

Research aimed to quantify the overhead seated BB shoulder press with respect to:

Active ROM (AROM)of with Passive ROM (PROM) of shoulder

AROM of spine segments – cervical, thoracic, lumbar

AROM of scapula

Statistical analysis involved comparing

‘in front’ with ‘behind’ overhead pressing

male to female

RESEARCH METHODS



PARTICIPANTS

33 participants (18 males, 15 females)

Sub-elite athletes - overhead/upper body sports who perform S&C in training at least 12 months

Age – 28.6 (4.7), 25.0 (4.1) years

Height – 182.3 (8.7), 167.0 (4.8) cm

Weight – 86.3 (10.3), 64.3 (4.4) kg

INITIAL MEASURES

Assessed passive ROM of the shoulder girdle, and anthrop measures of segment lengths

Anthropometry

Arm spam – 184.4 (7.9), 165.2 (4.8) cm

Elbow span – 98.5 (8.6), 91.1 (5.2) cm

Bi-acromial width – 40.7 (2.4), 36.7 (1.2) cm

PASSIVE SHOULDER GIRDLE ROM

(DEGREES – SD)

Measure Males Females Ideal

Shoulder flexion 158.8 (6.3) 167.9 (8.3) 160-180

Shoulder abduction 163.7 (13.0) 169.9 (7.0) 160-180

Shoulder horizontal flexion (behind frontal plane)

28.0 (12.6) 33.5 (4.7)No

consensus

Shoulder rotation internal (length of external rotators)

44.5 (15.8) 46.9 (11.0) 70

Shoulder rotation external (length of internal rotators)

84.7 (12.4) 89.3 (12.4) 90-100

SHOULDER FLEXION/ABDUCTION

TEST POSITION

Place arms above head with back flat

Flexion – ideal 180o

Abduction – ideal 180o

(American Orthopaedic Society)

SHOULDER ROTATION TEST

Start position - Arm bent 90o

20o off floor in front – ideal length external rotators

Arm touches floor above – ideal length internal rotators

SHOULDER JOINT ROM



0

20

40

60

80

100

120

140

160

180

200

Males

Females

Males typically larger

Females typically more flexible 3D MOTION ANALYSIS

Participants performed 4 sets of overhead press in seated unsupported position.

In front and behind the head, using 3RM loads

Started from top of movement with aid of spotter

Self selected feet position

Self selected tempo

RESULTS

CERVICAL SPINE

3RM

behind

Start

position

(degrees)

Minimum

(degrees)

Minimum

time (%)

Maximum

(degrees)

Maximum

time (%)

Range

(degrees)

Cervical

spine

flexion

Male 23.9 11.9 48.7 54.4 75.1 42.5

Female 17.1 13.8 59.0 30.6 66.1 16.8

Cervical

spine

rotation

Male 19.6 6.7 71.4 31.4 57.7 24.7

Female 11.4 3.5 74.6 17.5 54.7 14.0

3RM front

Cervical

spine

flexion

Male -8.5 -10.2 91.9 8.5 18.9 18.7

Female -8.4 -8.8 97.4 15.6 26.1 24.4

Cervical

spine

rotation

Male 15.2 12.5 63.8 18.5 26.0 6.0

Female 14.1 11.5 71.1 22.5 26.6 11.0

Normal curve 34-42o (Harrison et al 1997), Normal flexion/extension up to 45o Normal rotation up to 70o

Significant difference p>0.01 for all measures related to cervical flexion when comparing Front and Behind the head shoulder press for both male and female participants. Significant difference p>0.01 for Cervical rotation maximum time for both males and females and Cervical rotation range for males when comparing Front and Behind the head shoulder press.

Smaller number indicates top of press

Large number indicates bottom of the press

-20

-10

0

10

20

30

40

50

60

Start position(degrees)

Minimum(degrees)

Maximum(degrees)

Range (degrees)

Cervical Spine Flexion

Behind Male

Front Male

Behind Female

Front Female

Males achieved more cervical range of flexion during behind head and females for in front of the head

Behind head pressing started with loss of cervical curve and Front with normal cervical Lordosis

THORACIC & LUMBAR SPINE3RM

behind

Start

position

(degrees)

Minimum

(degrees)

Minimum

time (%)

Maximum

(degrees)

Maximum

time (%)

Range

(degrees)

Thoracic

spine

flexion

Male -10.0 -21.8 16.5 -6.3 71.9 15.5

Female -3.3 -16.4 19.7 -1.9 88.2 14.6

Lumbar

spine

flexion

Male -1.1 -8.7 37.4 1.8 56.7 10.5

Female 9.7 2.8 28.4 11.2 76.9 8.4

3RM front

Thoracic

spine

flexion

Male 10.5 -27.8 32.9 -13.6 74.5 14.2

Female 8.4 -24.5 38.5 -12.7 76.5 11.9

Lumbar

spine

flexion

Male -7.4 -13.2 55.2 -3.2 53.2 10.0

Female 3.2 -3.1 48.5 6.3 49.0 9.4

Significant difference p>0.01 for all Thoracic flexion measures for females when comparing Front and Behind the head shoulder press.

Significant difference p>0.01 for Thoracic flexion minimum time and maximum angle when comparing Front and Behind the head shoulder press

for males. Significant difference p>0.05 for lumbar flexion start angle, minimum angle, minimum time and maximum time when comparing Front and Behind

the head shoulder press for females.

Significant difference p>0.05 for lumbar flexion minimum time when comparing Front and Behind the head shoulder press for males.

Negative reading indicates thoracic extension

Negative reading indicates lumbar lordosis



-30

-25

-20

-15

-10

-5

0

5

10

15

20


Minimum(degrees)

Maximum(degrees)

Range(degrees)

Thoracic Flexion

Behind Male

Front Male

Behind Female

Front Female

Negative reading indicates thoracic extension

Minimums occurred with in bottom half of movement, whilst maximums occurred in top half

OH press to front achieved significantly more thoracic extension than to behind the head

-15

-10

-5

0

5

10

15


Minimum(degrees)

Maximum(degrees)

Range(degrees)

Lumbar Flexion

Behind Male

Front Male

Behind Female

Front Female

Females started with increased lumbar flexion, males in almost normal lordosis

Females stayed mostly in an increased lumbar flexion posture

Males stayed mostly in a lumbar lordotic posture

SHOULDER MOTION3RM

behind

Start

position

(degrees)

Minimum

(degrees)

Minimum

time (%)

Maximum

(degrees)

Maximum

time (%)

Range

(degrees)

Shoulder

flexion

Male 3.3 144.7 7.3 141.4

Female 22.2 155.0 14.6 132.8

Shoulder

abduction

Male 54.8 124.3 2.0 69.5

Female 56.6 123.4 3.2 66.8

Shoulder

rotation

Male 92.3 92.8 87.9 36.5 2.5 56.3

Female 79.3 79.3 99.6 25.9 6.5 53.5

Horizontal

flexion

Male -65.7 -66.9 75.1 -34.8 7.4 32.1

Female -57.4 -60.1 79.8 -32.1 6.7 28.0

3RM front

Shoulder

flexion

Male 6.7 135.9 1.4 129.1

Female 10.8 147.3 12.3 136.5

Shoulder

abduction

Male 32.8 125.7 1.0 92.9

Female 33.4 124.7 1.6 91.3

Shoulder

rotation

Male 66.5 67.7 85.5 25.3 4.0 42.5

Female 44.5 46.2 86.1 13.5 12.3 32.8

Horizontal

flexion

Male -61.7 -66.3 83.7 -37.5 7.9 28.9

Female -69.7 -70.2 96.4 -31.1 3.5 39.1

Significant difference p>0.05 for shoulder flexion maximum time for males and abduction starting angle and shoulder abduction range for males and

females when comparing Front and Behind the head shoulder press.

Significant difference p>0.05 for shoulder rotation minimum time for females and shoulder rotation starting angle, shoulder rotation minimum angle, maximum angle, and range for males and females when comparing Front and Behind the head shoulder press.

Significant difference p>0.01 for shoulder horizontal flexion minimum time and range when comparing Front and Behind the head shoulder press for

females.

Number indicates external rotation

Negative number indicates behind frontal plane

0

20

40

60

80

100

120

140

160

180


Maximum(degrees)

Range(degrees)

Shoulder Flexion

Male Behind

Male Front

Female Behind

Female Front

Passive ROM Males – 159o

Females – 168o

0

20

40

60

80

100

120

140


Maximum(degrees)

Range(degrees)

Shoulder Abduction

Male Behind

Male Front

Female Behind

Female Front


Females – 170o

0

10

20

30

40

50

60

70

80

90

100


Maximum(degrees)

Range(degrees)

Shoulder Rotation

Male Behind

Male Front

Female Behind

Female Front


Females – 90o

Passive ROM exceeded by males in behind the head OH press

At bottom of OH press AROM of shoulder rotation well within PROM limits



SCAPULA MOTION3RM behind

Start position

(degrees)

Minimum

(degrees)

Minimum

time (%)

Maximum

(degrees)

Maximum

time (%)

Range

(degrees)

Scapula

position in X

Male -50.0 -55.1 52.5 -35.6 30.4 19.5

Female -43.5 -47.7 56.6 -30.8 18.6 17.0

Scapula

position in Y

Male 15.2 15.2 90.9 48.0 4.1 32.7

Female 20.0 20.0 99.9 48.6 9.6 28.6

Scapula

position in Z

Male -63.9 -65.1 84.3 -37.4 3.6 27.7

Female -68.5 -69.9 87.6 -42.2 5.4 27.8

3RM front

Scapula

position in X

Male -54.4 -60.7 63.4 -36.8 16.2 23.9

Female -46.4 -51.8 66.0 -30.2 21.5 21.6

Scapula

position in Y

Male 15.2 12.7 90.9 49.1 8.5 36.5

Female 13.4 13.4 99.8 48.8 6.1 35.4

Scapula

position in Z

Male -52.7 -56.2 48.7 -34.2 28.0 22.0

Female -51.7 -59.1 49.9 -37.8 30.7 21.3

0

5

10

15

20

25

30

35

40

in 'X' in 'Y' in 'Z'

Scapula ROM

Male Behind

Male Front

Female Behind

Female Front

Movement about ‘X’ indicates Rotation –Greater rotation in Front

Movement about ‘Y’ indicates Tilting –Greater Tilting in Front

Movement about ‘X’ indicates Winging –Greater Winging in Behind

OH PRESSING

Key points:

AROM generally stays within PROM of the shoulder for

Flexion, Abduction, Horizontal flexion

Similar AROM range between genders for all measures except Shoulder rotation.

Significant differences between genders for starting spine postures

Resulted in thoracic extension during movement

OH PRESS BEHIND THE HEAD

Key points:

Greater movement of the cervical spine into cervical flexion and loss of normal curve

Requires greater ROM at shoulder in rotation than front OH press by more than 30o and this is reached at the top of the movement

Produced greater ‘winging’ of the scapula than Front

OH PRESS IN FRONT OF HEAD

Key points:

Allows more normal thoracic kyphosis commence position

Significantly greater thoracic extension

Produced significantly greater scapula ‘Rotation’ and ‘Tilting’ than Behind the head press.

MALES

Key points:

Start OH pressing with normal lumbar curve

Able to maintain lordosis through most movements

AROM of shoulder rotation during Behind press exceeded PROM



FEMALES

Key points:

Start OH pressing with increased lumbar flexion and loss of lordosis

Stay mostly in this posture during the press with greater maximum lumbar flexion than males

CONCLUSION

Shoulder press active ROM takes the shoulder musculature through ranges within normal passive motion except for males rotation.

Segmental spinal flexion/extension occurs within each phase,

Cervical spine moves through large ROM in both flexion and rotation –

males > in BN press,

females > in Front press

TAKE HOME MESSAGE

Shoulder rotation ROM must be assessed and corrected prior to overhead pressing

Poor PROM of shoulder may influence cervical spine posture during OH pressing

If Rotation ROM is corrected, behind the neck overhead pressing works shoulder through normal ROM.

DB press may be suitable short term alternative

Trunk and spine stability are important factors to consider when doing seated or standing overhead press.

A lack of stability in the spine will increase flexion-extension moments during overhead pressing and may require additional support via a back support.

Females may require additional trunk-core training to provide increased support to lumbar posture

Different athletes may suit different OH press based on posture and stability.

DR MARK MCKEANPHD CSCS AEP MESSA

Post Doctoral Research Fellow

University of Sunshine Coast

Australian Institute of Fitness Research

[email protected]

mailto:[email protected]

ASCA conference 2011 - Overhead Pressing

Health & Medicine

Transcript of ASCA conference 2011 - Overhead Pressing