Journal of Psychology in Africa, 2016 Vol. 26, No. 6, 555-557, © 2016 Africa Scholarship Development Enterprize 


Taylor & Francis Group 


Reaction time deficits incurred by Cumulative Mild Head Injury (CMHI) and Post-Concussion Symptoms (PCS) between contact and non-contact sport players: A prospective study 

Patricia Maite, Kathryn Nel, and Saraswathic Govender

‘Department of Psychology, Sefako Makgatho University, Garankuwa, South Africa Department of Psychology, University of Limpopo, Polokwane, South Africa 

*Corresponding author email: 

This prospective study investigated possible differential effects on reaction time and post-concussion symptoms contrasting contact and non-contact sport athletes. Participants were a purposive sample of football (soccer) players (n = 15) and volleyball players (17 = 15) from South Africa. They completed a reaction time measures pre-season and post-season. The data were analysed using the Fisher’s Exact Test and descriptive statistics. The study findings indicate a significantly higher sequential reaction time scores on the California Computerised Assessment Programme (CalCAP) for football players post-season compared to pre-season, and that some post-concussive symptoms (PCS) persisted after an initial concussion in the football-playing group or post-season. Results for ‘improved symptomology indicated that there was a small, significant difference between the football and volleyball groups post-season. 

Keywords: Cumulative Mild Head Injury (CMHI), post-concussive symptomology (PCS), football, volleyball 


Participants and setting. 

A purposive sample of male football players (n = 15) and male volleyball players (n = 15) was drawn from a population of 30 football players and 30 volleyball players. Exclusion criteria included any history of neuro cognitive deficit or illness, recent concussive injury, and/or substance abuse. The research took place at two universities in Gauteng, South Africa.


Mild traumatic brain injury (MTBI) is a common occurrence with contact sports (Lovell, 2009). In sporting circles MTBI is commonly referred to as concussion and is defined as a brief or negligible loss of consciousness (LOC) and memory with neither lasting for more than an hour (Menascu & Tschechmer, 2011). Risk is elevated with contact sports like football (Matser, Kessels, Lezak, Jordan, & Troost, 1999; Reilly, 1997; Tysvaer & Storli, 1989). By contrast, non-contact sports like volleyball have more of a risk for knee, hand and ankle damage (Briner & Kacmar, 1997). Nonetheless, a concussion cannot be ruled out with any physical sporting requiring repetitive rapid body motion determined by momentary demands on the field of play. There is evidence to suggest that concussion in contact sports often goes unrecognised and undiagnosed, which results in players not seeking medical attention (Al- Kashmiri & Delaney, 2006). 

Concussions are common head injuries in football (mostly from head-to-head or head-to-ground impact or head-to-goal-post injury) and are more likely to incur cognitive deficits than heading a ball (Cusimano et al., 2014). This study sought to investigate the effects of Cumulative Mild Head Injury (CMHI) and post-concussive symptoms (PCS) of football players and compare them to a non-contact sport control group (volleyball players). The research questions related to the goal were a) to examine the extent of cognitive impairments among football players and volleyball players’ pre- and post-season, and b) to determine differences in reaction time incurred by CMHI and PCS between football and volleyball players. 

Instrument The athletes completed a demographic questionnaire which required relevant medical information. To check for post concussive symptomology the Rivermead Post-Concussion Symptom Checklist (RPCSC) was used (King, Crawford, Wenden, Moss, & Wade, 1995). On this measure, high test reliability scores of 0.89 and 0.72 have been found (Eyres, Carey, Gilworth, Neumann, & Tennant, 2014). 

The California Computerised Assessment Package (CalCAP: Miller, 2001) is very sensitive to diffuse brain damage, which is incurred through CMHI, it was thus used to measure differences between the contact sports players (football) and the non-contact controls (volleyball). It is a measure of specific cognitive deficits: Simple Reaction Time, Choice Reaction Time, and Sequential Reaction Time. Previous studies reported high internal consistency scores of between 0.77 and 0.96 for scores from the CalCAP (Miller, 1995; Worth, Savage, Baer, Esty, & Navia, 1993). 


Permission to conduct the research was granted by the participating universities and their ethical committees. Football and volleyball control participants had the research and their rights explained to them and were required to sign written consent forms. 

Pre-season testing was conducted in order to get a baseline measure before the start of the season. The testing took place at an appropriate location at the participating universities’ sports centres. Players were assessed individually. 

The participants had to complete the demographic and medical symptom checklist and the PCS checklist. The participants were then assessed on CalCAP. The baseline testing took approximately 45 minutes for each participant, slightly longer than post-season testing as they had to fill in medical information which would either include or exclude 

them from the study. 

Post-season testing participants completed the PCS checklist questionnaire and were then assessed on the CalCAP. The average time between baseline and post season test for both the football and the volleyball controls was eleven months. The same venues and data administration procedures were used both pre- and post-season. Researchers were the same to obviate administration bias. As the demographic and medical questionnaire did not have to be filled in post-season, testing time was shorter at approximately 25 minutes per participant. 

The players provided individual written consent forms for the study. The participants were informed that if they felt uncomfortable or upset during or after the assessment they would be referred to an appropriate counsellor. 

Reaction time findings

At pre-season testing, volleyball control participants had a faster mean (M) simple reaction time in milliseconds [ms] (335.5 ms, SD +68.9)) than the football participants (M = 386.3 ms, SD +101.7) on Simple Reaction Time 1 (though not statistically significant, p = 0.110). At the end of the season, both the football and the volleyball control group did not differ significantly (p = 0.120). Choice Reaction Time results revealed larger (though not statistically significant (p = 0.429) post-season differences between football players and volleyball controls. Football players had slightly slower mean reaction times post-season (M= 445.8 ms, SD #66.5) than pre-season (M = 444.2 ms, SD +41.0). It is postulated that this could be due to the effects of CMHI as a result of on-field incidents. This result is underpinned by the results of Sequential Reaction Time 1 which revealed a small, statistically significant difference between the football playing group (M = 542.7 ms, SD 

76.6) and the control group (M = 486.00 ms, SD +63.1) post-season (p = 0.033). Sequential Reaction Time 2 results revealed that the football players’ pre-season testing indicated a faster mean reaction time (M = 565.7 ms, SD #104.3) than the control group (M= 642.1 ms, SD =121.2), but it was not statistically significant (p = 0.170). At post season testing, the football players’ reaction time improved (M = 553.4 ms, SD +91.6) as did the control group (M = 601.1 ms, SD =92.2). However, there was no significant difference between the groups (p = 0.157). It appears that playing fast-paced sports, which require dexterity and skill, improves reaction times during the season with or without reaction time training. 

Data analysis

The cognitive profiles of the contact sport (football players) and the non-contact sport controls (volleyball players) were analysed using the Mean (M) and Standard Deviation related to measures of 1 and 2, measured in milliseconds (ms), of the abbreviated CalCAP battery. 

Data were also analysed using Fisher’s Exact Test for the within and between group comparison of the summary of PCS between the football and volleyball control participants at pre-season (baseline) test and post-season (end of season) testing, 

Results and discussion

Pre-season (baseline) and post-season testing (end of season) across the reaction time measures are presented first, followed by pre-season (baseline) and post-season (end of season) findings for the post-concussion measure. Figure 1 presents a summary of the findings on the reaction time measure. 

Post-concussion symptoms

The total frequency of the controls’ symptomology on the PCS checklist revealed that only 6% of these respondents, as opposed to over a quarter (26.67%) of the football group, experienced headaches. Headaches were the most commonly reported PCS measure by football players after sustaining CMHI, particularly in the acute phase. About 50% of the football players reported that they ‘sometimes’ experienced problems with attention and concentration, easily got angry and hurt, and often experienced being nervous or anxious. These symptoms are commensurate with PCS in the chronic phase (Meeham & Bachur, 2009) which supports the small but significant finding on CalCAP Sequential RT 1. 

The results on the Fisher Exact Test for ‘worse symptomology revealed that there were no significant differences between the football and control groups (p = 0.62). However, the results for ‘improved symptoms revealed that there was a small, significant difference between the football group and volleyball controls with 1.3% of the football group reporting ‘improved’ symptoms pre-season as compared to 17.6% of the control group (p= 0.002). This significant outcome suggests chronic PCS in these football players. 

Post Figure 1: Pre-test versus post-test mean scores in milliseconds (ms) on the Choice Reaction Time measure on CalCAP for football (soccer) and the volleyball controls 

Conclusion Findings of this study point towards the possibility that football players are vulnerable to sustaining concussion and CMHI during play (Matser et al., 1999; Reilly, 1997; 

Tysvaer & Storli, 1989) as suggested by their depressed reaction time scores and elevated post-concussion scores. The small sample size and purposive sample suggest that the findings cannot be generalised to football players in general. Future studies should be larger and use randomised samples so that more definitive findings can be made. 

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