Very little research is available in the field of elite freestyle ski and snowboarding. More specifically, the events of halfpipe and slopestyle and big air lack comprehensive evidence informing athletes and coaches what physical stresses are imposed on the athlete during training and competition. And secondly, what training should be completed to improve rider performance and also minimise the risk of injury in an extreme high risk sport. With this in mind, this presentation provides an insight in a body of applied research completed by MPhil researcher, John Noonan. Incorporating findings from pilot testing and a key study, which presents biomechanics information collected from GB Park & Pipe athletes competing in freestyle snowsport competition. The findings characterise specific biomechanics demands and present considerations for coaches and scientists working with freestyle snowsport athletes.

1. The Biomechanical
Demands of Elite Freestyle
Snowboard Athletes
John Noonan, BSc (Hons), MPhil, ASCC
Strength and Conditioning Coach
Performance Consultant

2. Freestyle
‘GB Park & Pipe’

4. Re-training the Slopestyle athlete

5. Common Practice
:
A classic problem …

6. Screening Day 1 (August 2013) - injury “stretched” R ACL

13. Results - RTS (8wks)
August - Injured
• 65.5 kg
• Knee effusion
• Atrophy to Quadriceps
• No lifting
• Poor movement control
• Limited understanding of movement
• No Jumping
September - Return
• 67 kg
• No effusion
• Quad hypertrophy
• Squat 3 x 120 kg
• Movement control continually imp.
• Improved movement awareness
• Completed plyometric progressions
• Completed progressive loading
programme

14. Learning the ‘Triple’

15. Brilliance
Extreme
Trauma

16. 0
2.25
4.5
6.75
9
August 2012/13 August 2013/14
7
6
44
2
9
Resolved + Treatment Surgery
Ongoing Treatment
Injuries
*Knee*
0
1.5
3
4.5
6
August 2012/13 August 2013/14
00 0
1
3
6
Resolved + Treatment Surgery
Ongoing Treatment
Ankle
0
0.5
1
1.5
2
August 2012/13 August 2013/14
0
1
2
0
11
2
1
Adductor Strain Gluteal Strain
Hamstring Strain Labral Lesion
Hip
0
2.5
5
7.5
10
August 2012/13 August 2013/14
5
4
9
10
5
7 7
6
Lumbar/ Sacral/ ilial Thoracic
Cervical Rib
*Spine*

17. 0
0.75
1.5
2.25
3
August 2012/13 August 2013/14
2
3
Gastroc/ Soleus/ Peronial/ Anterior Tibialis
Injuries cont.
Lower-limb soft tissue
0
2
4
6
8
August 2012/13 August 2013/14
10 10 01 01
3
8
Rotator Cuff Dislocation
A/C Joint Dislocation Clavical Fracture
Laberal Lesion
Shoulder
Concussion!
0
0.75
1.5
2.25
3
August 2012/13 August 2013/14
3
0
Head Trauma
???

18. What are the sports demands?

20. ….how should we train Free Sport athletes?

21. 1. Landing capability is critical to mitigate high injury rates and the potential for
injuries:
**Non investigated requirements of jump landing performance:
• Muscular demands; Muscular MVC and eccentric RFD
• Landing kinetics; Landing acceleration, muscular involvement (EMG)
• Landing kinematics; 3D passive joint control, joint angular velocity
• Differences between types of landing, specifically off-axis rotations
Freestyle Physical Demands
What the research currently suggests -

22. Slopestyle
Pilot Investigation

26. Pilot Testing
Jump 1: “Went big”

27. Pilot Testing
Jump 2: “Easy”

28. “Heavy” “Light” “Mod” “Heavy” “Light”
VerticalAcceleration(g)
0
10
20
30
40
Run 1 Run 2 Run 3 Run 4 Run 5
4.9
9
6.85.6
8.5
30.4
28.229.4
26.825.9
Board Body
Subjective
Rating:
Pilot testing:
Peak acceleration during landings

30. Body = 6.8 g

31. Body = 4.9 g

32. Pilot testing: Key Findings
Board variables:
• In-run speed
• Jump height (gravity)
• Landing high/ low on the transition effects peak acceleration
• Landing execution influence magnitude of loads experienced
Body Variables:
• Board fluctuations
• Trunk angle
Outcomes:
*Transient impact; GRF transferred from board to the body

33. Figure 7.
Peak acceleration (g) during a single snowboard jump landing on outdoor artificial dry-ski slope (pilot). Shows a wave
curve taken from a 100 Hz tri-axial accelerometer mounted to a snowboard; 10 data points captured within 100ms
during landing phase (n=1).
The problem with a 10 Hz Accelerometer …

34. Slopestyle Research
Step 1. Evaluate the suitability of available technologies for
biomechanical assessment of snowboard landings in training (pilot
study).
Step 2. Evaluate the suitability of technologies for biomechanical
assessment of snowboard landings in the lab.

36. Slopestyle Research
Step 1. Evaluate the suitability of available technologies for
biomechanical assessment of snowboard landings in training (pilot
study).
Step 2. Evaluate the suitability of technologies for biomechanical
assessment of snowboard landings in the lab.
Step 3. Measure the biomechanical demands of snowboard
landings on snow.

37. Slopestyle
Main Investigation

38. 15.2m
6.2m
4.5m
2m

43. Main Findings

44. Figure 12. Group mean (±SD) snowboard resultant acceleration (g) recorded during the landing phase for all
trials, for all subjects (n=5) during regular, switch and 360 deg rotation jump landing conditions.

45. Figure 13. Mean knee angle measured in degrees (deg) during the post-IC phase of landing for the
regular (n=1), switch (n=3) and 360 deg rotation (n=3) during the first 100ms of landing for each type of
landing.
0
10
20
30
40
50
60
70
80
90
100 1
4
7
10
13
16
19
22
25
28
31
34
37
40
43
46
49
52
55
58
61
64
67
70
73
76
79
82
85
88
91
94
97
100
Meankneeangle(deg)
Time post IC (ms)
REG mean (n=1) SW mean (n=3) 360 deg mean (n=3)
Knee flexion
Knee extension

46. Figure 14. Group mean knee angular velocity measured in degrees per second (deg/s) during the
post-IC phase of landing, for the switch (n=2) and 360 deg rotation (n=2) during the first 100ms of
landing for each type of landing.
0
50
100
150
200
250
300
350
400
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97
101
Kneeangularvelocity(d/sec)
Time post IC (ms)
SW mean (n=2) 360 deg rotation mean (n=2)

47. Figure 15.
Figure 16.
Figure 17.
*
*
Regular
Switch
360d
Figure 15. Group summed mean
iEMG and (±SD) pre (200 ms) and
post (200 ms) IC phase
of landing, recorded over 3 trials for
the BF, RF, ST, VL and VM muscles
in the regular jump
landing condition (n=5).
Figure 16. Group summed mean
iEMG and (±SD) pre (200 ms) and
post (200 ms) IC phase
of landing, recorded over 3 trials for
the BF, RF, ST, VL and VM muscles
in the switch jump
landing condition (n=5).
Figure 17. Group summed mean
iEMG and (±SD) pre (200 ms) and
post (200 ms) IC phase
of landing, recorded over 3 trials
for the BF, RF, ST, VL and VM
muscles in the 360 deg
rotation jump landing condition
(n=4).

48. Figure 18. Group mean summed
(±SD) iEMG for pre-IC landing
phase (200 ms), recorded
over 3 trials for BF, RF, ST, VL
and VM muscles in regular,
switch and 360 deg rotation jump
landing conditions for n=4, and
regular and switch landings for
n=5 .

49. Summary of Findings
• Provided an understanding of joint motion and corresponding muscular activity measured during 3 typical landing
conditions by elite snowboard athletes of the GB Park & Pipe team - information previously absent from scientific
literature.
• Largest board accelerations and corresponding peak muscle activity found in order of (1) regular, (2) 360 deg and (3)
switch jump landings.
• Higher overall mean iEMG activation post, versus pre moment of landing (initial contact - IC). With the exception of
higher pre activation found in the Bicep Femoris (BF) and Vastus Lateralis (VL) groups in regular and switch condition.
• Prior to landing, the group produced higher iEMG quadricep activation pre-IC (RF, VL, VM) during Switch and 360 deg
conditions. Higher BF activity pre-IC during 360 deg condition. Highest semitendinosus (ST) activity recorded pre-IC
in the regular landing condition.
• Found greater peak iEMG hamstring pre-activation in preparation for more severe landings. Increased landing
acceleration = increased muscular anticipation.
• Found athletes utilised greater overall knee flexion during switch and 360 deg landings. This was concomitant with
higher peak quadricep (RF, VM, VL) activity - possible strategy to constrain high impact landings? Also found in other
studies; Zhang et al., 2000, Zhang et al., 2008.
• Highest iEMG hamstring muscle activation occurred during rotational (360 deg) jump landings, in particular lateral
hamstrings (BF) when compared to hamstring activity in regular and switch jump landings.
• Despite increased technical demands created by rotational landings, highest overall peak (iEMG) muscle activity was
recorded during regular (straight air) jump landings, which also coincided with larger peak landing acceleration values.
Athletes also landed with less knee flexion which may have attenuated higher peak iEMG values.

50. Implications for the Sport
• Differences in landing strategies can be seen between athletes, and thus the total contribution of muscular activity and
the relative joint loading in landings differ between individuals. And because the perfect technical model does not exist
coaches should employ a combined approach to optimise athlete ‘readiness for landings’, incorporating the following;
1) improve the ability to execute landings with sound technical ability, under a range of conditions, and 2) focus efforts
on increasing the physical characteristics (max strength, speed-strength, power) to withstand high impact loading.
• Teach/coach athletes how to create pre-tension/activation prior to the instant of landing to achieve sufficient landing
stiffness to withstand severe, jump landing impacts. Developing athletes’ rate of force capability is essential to tolerate
rapid and large ground reaction forces, and mitigate the risk of lower-limbs sports injuries from a lack of landing
physical preparation.
• Findings highlight the importance of developing high muscular strength, in particular, isometric and eccentric, and
eccentric rate of force qualities in the lower-limb structures to; 1. constrain high impact landing forces, 2. reduce knee
instability and connective tissue loading, 3. Improve performance of snowboard jump landings.
• Jumps involving spins/rotations significantly increases the relative contribution of quadricep and lateral hamstring
activation in the moments prior to landing, when compared to regular landings. It’s possible this occurs in anticipation
for complex landings and to increase multi-planar knee control during complex landings. Physical preparation
programmes should develop rapid eccentric braking of the mentioned structures, and develop movement-skill control
to optimise performance in rotational snowboard landings actions.

51. Glossary of terms:
KA - Knee angle
KAV - Knee angular velocity
iEMG - mean EMG
IC - Initial contact
RFD - Rate of force development
SS - Slopestyle
BF - Bicep Femoris
RF - Rectus Femoris
ST - Semitendinosus
VL - Vastus Lateralis
VM - Vastus Medialis

52. Thank you
John_M_Noonan
jcnoonan85@gmail.com