| Date | May 2021 | Marks available | 2 | Reference code | 21M.2.SL.tz0.1 |
| Level | Standard Level | Paper | Paper 2 | Time zone | time zone 0 |
| Command term | Discuss | Question number | 1 | Adapted from | N/A |
Question
A study investigated the magnitude of the impact force, in Newtons (N), at the shoulder during tackling in 35 experienced rugby union players. The researchers looked at the effect of the following variables on the impact force at the shoulder:
- Condition 1: Shoulder pads (with and without)
- Condition 2: Shoulder (dominant versus non-dominant)
- Condition 3: Setting (in a laboratory versus on a rugby field)
[Source: Steve Haag/Gallo Images/Getty Images.]
Table 1 shows the mean maximum impact force in Newtons (and standard deviation) for Conditions 1 and 2.
[Source: Reprinted from Journal of Science and Medicine in Sport, [e-journal] 14, Usman, J., Mcintosh, A. S.,
Fréchède, B., 2011. An investigation of shoulder forces in active shoulder tackles in rugby union football. pp.547-552.
with permission from Elsevier. Available at: https://www.jsams. org/article/S1440-2440(11)00106-X/pdf
[accessed 05 September 2019].]
Table 2 shows the mean maximum impact force for trials conducted in the laboratory and on the field (Condition 3).
[Source: Reprinted from Journal of Science and Medicine in Sport, [e-journal] 14, Usman, J., Mcintosh, A. S.,
Fréchède, B., 2011. An investigation of shoulder forces in active shoulder tackles in rugby union football. pp.547-552.
with permission from Elsevier. Available at: https://www.jsams. org/article/S1440-2440(11)00106-X/pdf
[accessed 05 September 2019].]
The possibility of brain injuries is a concern in certain sports. A recent study tested the effect on the impact force (N) of adding a soft-covering cap to a helmet when dropped from a set height. The graph shows the results for three different brands of helmet, A, B, and C.
[Source: Breedlove KM, et al. The Ability of an Aftermarket Helmet Add-On Device to Reduce Impact-Force Acceleration
During Drop Tests. J Athl Train. 2017;52(9):802-808.]
Identify which shoulder has the greatest mean impact force.
Calculate the difference, in Newtons, between mean maximum impact force for dominant and non-dominant shoulders for players wearing pads.
Using the data, discuss the hypothesis that wearing padding could reduce the incidence of injuries to the tackler in rugby union.
Suggest reasons for the lower impact forces recorded in the laboratory setting.
Evaluate field and laboratory testing for human performance.
Identify the brand of helmet that demonstrated the lowest mean impact force.
Deduce the effect of having a soft-covering cap on the impact force of the different helmets.
Markscheme
dominant ✔
dominant without pads ✔
1697−1573 ✔
= 124 <N> ✔
Accept the subtraction in the converse.
Units not required.
shoulder impact force was lower for both dominant and non-dominant with padding
OR
for dominant shoulder impact force was highest without padding <1719 versus 1697>
OR
for non-dominant shoulder also highest without padding <1648 versus 1573> ✔
there is a possible reduction in injury / hypothesis is supported✔
Data must be interpreted; numbers don’t need to be stated.
ground surface may have allowed for the player to apply more force / drive from their legs ✔
differences in footwear may enable better force application ✔
landing ability may have allowed more force to be applied in field e.g. synthetic surface may not encourage proper technique ✔
players may have found it easier to apply themselves mentally to the task in the real environment / greater levels of arousal✔
field measurement might have systematic error / as not as accurate. ✔
MP3, 4, 5 accept in the converse.
Lab:
greater accuracy / reliability of measured variable / tool used e.g. O2 extraction for maximal oxygen consumption (VO2max) ✔
greater control of environmental factors ✔
Field:
more specific to performance environment / greater ecological validity / motivate the performer to perform to their optimal level ✔
field tests use less specialised / technical equipment / expertise ✔
easier to test large numbers e.g. Cooper’s 12 minute run ✔
cheaper ✔
Accept in the converse.
Award [1 max] for each category of response.
Award [3 max] if only strengths or limitations.
Note: accept ‘inaccurate’ as meaning ‘not as accurate’, if this is considered an ESL issue.
helmet A ✔
for all helmets, with cap the results/impact forces are lower
OR
the cap has a greater effect on helmet C than the others ✔
standard deviations for all overlap/there is very little difference between the conditions, so there is no significant difference between them ✔
p value shows no significant effect ✔
Examiners report
The calculations and interpretation of the graph was generally very well done.
The calculations and interpretation of the graph was generally very well done.
Discussion of the hypothesis and use of control was solid with most students earning the two marks on offer.
Most candidates were unable to put themselves into this situation and imagine what the possible issues beyond "motivation" or "accuracy" could cause an issue.
Generally candidates were able to gain some marks here. This is a 4 mark question and candidates may have missed out because they did not provide enough points. They must be aware that if they say that laboratory testing may use more expensive equipment they cannot get the mark again for saying that the equipment for a field experiment is cheaper.
1(d) and (e) were well done by the candidates.
1(d) and (e) were well done by the candidates.
