Skip to main content

Table 1 Studies investigating the effects of anticipation on linear (g) and rotational (rad · s−2) head accelerations

From: The Effects of Anticipation and Visual and Sensory Performance on Concussion Risk in Sport: A Review

  Participants, sport and level Protocol Anticipation condition Linear head acceleration (g) Rotational head acceleration (rad · s−2) Muscle activity (mV) Significant findings Limitations
In vivo studies
 Kuramochi et al. [47] 9 healthy males
19–30 years
Direct impact to the forehead while sitting in a chair
Impact: 4 kg weight released from 25°
Uniaxial accelerometer
Rectified EMG averaged over onset duration for SCM and TRP
Anticipated
(eyes opened)
Unanticipated
(eyes closed)
3.85 ± 0.33
(37.8 ± 3.3 m · s−2)
3.72 ± 0.24
(36.5 ± 2.4 m · s−2)
N/A
N/A
R/L SCM:
6.3 ± 1.5*/
8.3 ± 2.5*
R/L SCM:
17.9 ± 3.7/
22.4 ± 5.4
Anticipation did not affect the linear head acceleration
No difference in the onset latency between conditions
Unanticipated condition elicited greater muscle activity than the anticipated condition
A strictly laboratory-based study; findings limited for extrapolating the results to concussive head impact intensities during game play
Head accelerations significantly below the proposed 85 g injury threshold
Limited to sagittal plane movement
 Mihalik et al. [30] 16 male Bantam-level ice hockey players (elite youth)
Average age:
14.0 ± 05 years
Experience:
7.8 ± 1.7 years
Data collected from single team over 54 games:
HIT system (> 10 g)
Qualitatively assessed body position from video analysis (CHECC List)
Location on the ice (along playing boards, or on the open ice)
Anticipated (‘saw hit coming’), good body position
Anticipated, bad body position
Unanticipated regardless of body position
20.7
21.4
22.6
1409.4*
1420.4*
1550.0
N/A
N/A
N/A
Anticipation was not associated with lower linear head accelerations
For the medium intensity impacts, anticipation was associated with a reduced severity of rotational head acceleration
Anticipation had no effect on head acceleration for the highest intensity collisions (> 75 percentile of collisions according to the HIT severity profile)
Small convenience sample: various player positions, single team, 1 season
Investigator’s judgement on the player’s anticipation status from video footage only
 Hasegawa et al. [48] 12 male high school rugby players
Average age: 16.8 years
5 rugby tackles to the chest
Triaxial accelerometer measured head accelerations of the attacker and defender
EMG to assess bilateral masseter and SCM1
No clenching instruction (unanticipated)
Tightly clenched (anticipated)
A: 2.64 ± 0.33
D: 2.86 ± 0.23
A: 2.16 ± 0.50*
D: 2.30 ± 0.27*
N/A
N/A
Masseter A/D:
0.22 ± 0.12/0.29 ± 0.18
SCM A/D:
0.60 ± 0.19/0.70 ± 0.23
Masseter A*/D*:
0.55 ± 0.25/0.73 ± 0.46
SCM A/D:
0.62 ± 0.18/0.77 ± 0.24
Clenching increased activity of the masseter muscle and decreased linear head acceleration
Muscle activity onset occurs prior to body contact
Small sample size
Analysed sub-concussive intensity head impacts to minimise injury risk; cannot confidently extrapolate results to concussive head impact intensities
Rotational head accelerations not analysed
 Narimatsu et al.
[49]
11 male high school soccer players
Average age:
17.2 years
5 trials of heading a soccer ball under 3 conditions
Triaxial accelerometer measured head accelerations
EMG 1 to assess bilateral masseter and SCM
Ball projected approx. 9 m from JUGS soccer machine (initial motor velocities set at 28 m · s−1 (RM) and 38 m · s−1 (LM)
No clenching instruction
(unanticipated)
Clenched w/o mouthguard
(anticipated)
Clenched with mouthguard
(anticipated)
28.4 ± 7.0
23.9 ± 6.2*
21.5 ± 4.6*
N/A
N/A
N/A
Masseter: 44.0 ± 38.2
SCM: 68.6 ± 47.7
Masseter: 132.7 ± 76.5*
SCM: 133.5 ± 74.2*
Masseter: 154.0 ± 99.3*
SCM: 159.3 ± 76.8*
Clenching in anticipation of heading a soccer ball increases muscle activity of masseter and SCM muscle compared to the no clenching instruction condition only (no mouthguard and clenching interaction), and reduces linear head acceleration
Masseter and SCM active before headed ball
Small sample size
Not game-like intensity, intentionally eliciting lower intensity head impacts to minimise head injury risk; cannot confidently extrapolate to concussive head impact intensities
 Schmidt et al. [50] 32 male high school conference 3A varsity American Football players
Average age:
16.7 ± 0.9 years
Data collected during game play
HIT system to assess head accelerations
Video analysis to subjectively classify impacts as anticipated or unanticipated
Anticipated
Unanticipated
25.9
26.5
1605.5
1621.3
N/A
N/A
There was a trend (p = 0.07) towards a lower linear head acceleration when the impact was perceived to be anticipated Small convenience sample: various player positions, single team, over 1 season
Limitations of video analysis for determining anticipation level
No assessment of concussion risk
No assessment of whether perceived anticipation resulted in players moving into a protective position
Simulations and modelling        
 Jin et al. [51] Simulated impacts using finite element model
Head and neck complex of the Global Human Body Model with validated helmet model
27 pairs of Hill-type muscle elements
Reconstructed concussive and non-concussive American Football-related head impacts
Magnitude and timing of impact for simulation and experimental data within 10% of each other; peak impact force approx. 10,000 N
4 conditions simulated
(1) No muscle activity
(2) Reactive muscle response (onset at impact, 55 ms to peak activation)
(3) Pre-activation response (40 ms before impact)
(4) Pre-activation response (40 ms before impact) with 200% strength
113.36
112.18
111.75
110.59
29.25 rad · s−1
26.90 rad · s−1
22.72 rad · s−1
20.16 rad · s−1
N/A
N/A
N/A
N/A
Anticipatory activation of neck musculature reduced injury criteria
No change in the injury criteria with double muscle strength, or reactive activation compared to no activation
No differences in linear accelerations of the head
Pre-activation reduced peak rotational velocity (18.1–31.0%)
Theoretical computational model only
Results largely influenced by the model constraints used
 Eckersley et al. [52] Simulated model
Duke University Head and Neck model
Simulated 4 head impact conditions with 6 neck muscle activity conditions at 8 impact sites
Impacts:
(1) Impact of high speed object in flight
(2) 80 g helmet-to-helmet impact (short duration)
(3) 80 g helmet-to-helmet impact (longer duration)
(4) 40 g helmet-to-helmet impact
(1) Relaxed (min. activation to maintain head stability)
(2) Maximally activated neck musculature
(3) Maximally activated neck flexors
(4) Maximally activated neck extensors
N/A
N/A
N/A
N/A
Lowest value


N/A
N/A
N/A
N/A
Magnitude of cervical muscle force does not influence short-term (< 50 ms) head kinematics
Impacts to the side of the head, higher than ear level consistently produced highest peak resultant angular acceleration
Musculature presumably active at time of impact to simulate pre-activation
Values not reported
Theoretical computational model only
Results largely influenced by the model constraints used
Estimated constraints used to simulate a direct impact to the head, rather than using data from real concussive head impacts
  1. A attacker, D defender, HIT head impact telemetry, LM left motor, RM right motor, SCM sternocleidomastoid muscle activity, TRP trapezius
  2. 1Details of the EMG analysis not provided
  3. *Significant difference compared to the unanticipated condition