Anterior knee pain and its extrinsic risk factors among runners in under-resourced communities in Ekurhuleni, Gauteng, South Africa

Background Various factors predispose athletes to anterior knee pain (AKP), making a holistic assessment with rehabilitation inevitable. Due to minimal rehabilitation services in under-resourced communities, runners are less likely to report this injury to medical professionals compared to runners in better resourced communities. Objective The purpose of this study was to report on the prevalence of AKP among runners in under-resourced communities and to determine the extrinsic risk factors for this injury. Methods This was a cross-sectional study of 347 runners in total. Convenience sampling was used to recruit 183 participants aged between 13 and 55 years with no previous history of knee surgeries, traumatic or degenerative knee conditions. Questionnaires were used to collect data on the prevalence of AKP and extrinsic risk factors. The SPSS (version 25) was used to analyse the data. Data were presented as frequencies and percentages and the results from chi-square and logistic regression tests were provided. Results Forty percent (40%) of participants presented with AKP, particularly males (n=106, 58%), young runners (n=94, 51%) and those with 3–5 years of running experience (n=57, 31%). Anterior knee pain was associated with age (X2=6.484, p=0.039) and running experience (X2=8.39, p=0.04). The following extrinsic risk factors contributed to AKP significantly: training load (p=0.04, odds ratio [OR]=1.23), warm-up (p=0.04, OR=1.57)’ running shoe condition (p=0.04, OR=0.14) and running surface (p=0.05, OR=1.2). Conclusion A substantial presence of AKP and its extrinsic risk factors were found among all participants. These outcomes suggest that extrinsic risk factors should also be considered when managing AKP among runners.

Anterior knee pain (AKP) is the most problematic symptom among many runners worldwide (15-45%), with females, adolescents and young adults being the most affected. [1,2]unners usually describe AKP as pain on the anterior aspect of the knee, beneath or around the edges of the patellar.Their pain is usually triggered or made worse by running, squatting, going up and down stairs, cycling and jumping activities.Anterior knee pain is a consequence of overuse but can also be experienced after an acute and traumatic injury, such as falling on the knee.Any activity that requires consistent compression force on the patellofemoral joint may trigger this kind of pain.The cause of AKP is usually multifactorial. [3]nterior knee pain has a negative impact on the quality of life (QOL) of many athletes.Athletes with AKP may experience various problems such as physical limitations, emotional and social difficulties which may have a detrimental effect on their well-being and ability to perform optimally. [4]These experiences may also affect athletes' participation in their rehabilitation programmes and their return to sport.Apart from the physical features, anterior knee pain also has nonphysical features which may influence the recovery of patients.Theses non-physical characteristics may include psychosocial-, emotional and mental features.A previous study highlighted the negative impact of AKP on the QOL of runners from underresourced communities, recommending the need to address the non-physical features when formulating strategies to improve QOL among the running population with AKP. [5]unners can be predisposed to AKP through intrinsic and external factors.Intrinsic factors may include a weak vastus medialis oblique, tight gastrocnemius-soleus muscle complex, dysfunction of the hip muscles, foot pronation, generalised joint laxity, limb length discrepancy, patellar malalignment and patellar hypermobility. [6]In particular, tight hamstrings and weakness of the iliotibial band and quadriceps, weak hip control muscles and patellar tilt abnormalities were found to be significant when associated with AKP in an under-resourced community in South Africa. [7]It is therefore critical that the intrinsic risk factors be considered in the management of AKP in order to improve management outcomes. [7]stablishing extrinsic risk factors is another important component to be considered when dealing with the management of AKP.Extrinsic factors which are external to the body may include: the action of running, the level of participation (including training and competition), other types of physical activities and the way they are performed, running surfaces, environmental conditions, and the effect of the equipment encountered during physical activities, e.g.air resistance, gravity and ground reaction forces, and shoes. [2]No previous studies have reported on the association between extrinsic risk factors and AKP in runners from under-resourced South African communities.
South African healthcare is challenged due to the lack of health resources and scarce professional skills. [8]Most healthcare facilities in rural or peri-urban communities do not have rehabilitation healthcare professionals, which results in patients not receiving adequate and holistic rehabilitation services.According to these authors' experience within physiotherapy clinical settings, injuries associated with AKP are experienced by many runners from these under-resourced communities, which often results in the end of their running careers due to lack of rehabilitation services.This in turn leads Background: Various factors predispose athletes to anterior knee pain (AKP), making a holistic assessment with rehabilitation inevitable.Due to minimal rehabilitation services in under-resourced communities, runners are less likely to report this injury to medical professionals compared to runners in better resourced communities.Objective: The purpose of this study was to report on the prevalence of AKP among runners in under-resourced communities and to determine the extrinsic risk factors for this injury.Methods: This was a cross-sectional study of 347 runners in total.Convenience sampling was used to recruit 183 participants aged between 13 and 55 years with no previous history of knee surgeries, traumatic or degenerative knee conditions.Questionnaires were used to collect data on the prevalence of AKP and extrinsic risk factors.The SPSS (version 25) was used to analyse the data.Data were presented as frequencies and percentages and the results from chi-square and logistic regression tests were provided.Results: Forty percent (40%) of participants presented with AKP, particularly males (n=106, 58%), young runners (n=94, 51%) and those with 3-5 years of running experience (n=57, 31%).Anterior knee pain was associated with age (X 2 =6.484, p=0.039) and running experience (X 2 =8.39, p=0.04).The following extrinsic risk factors contributed to AKP significantly: training load (p=0.04,odds ratio [OR]=1.23),warm-up (p=0.04,OR=1.57)' running shoe condition (p=0.04,OR=0.14) and running surface (p=0.05,OR=1.2).Conclusion: A substantial presence of AKP and its extrinsic risk factors were found among all participants.These outcomes suggest that extrinsic risk factors should also be considered when managing AKP among runners.Keywords: patellofemoral pain, predisposing factors, athletes, poor resourced communities S Afr J Sports Med 2019;31:1-6.DOI: 10.17159/2078-516X/2019/v31i1a6090 to poor QOL for these runners.This study's objective was therefore to determine the prevalence of AKP and its extrinsic risk factors among runners in under-resourced communities in Ekurhuleni, Gauteng province, South Africa.

Methods
The population for this cross-sectional study included 183 out of 347 long-distance recreational runners from six developing clubs in under-resourced, peri-urban communities in Ekurhuleni, Gauteng province, South Africa.The same methodology was used as in the authors' previous study. [7]hese runners were aged between 13 and 55 years with no history of knee surgery, traumatic or degenerative knee conditions.As in a previous study by these authors a convenience sampling method was used. [7]Runners were recruited during their training sessions from six different clubs.A Raosoft statistical tool was used to calculate the study's sample size of 183 runners, taking into consideration a 95% confidence level, 5% margin of error and 50% response distribution (http://www.raosoft.com/samplesize.html).Participants were recruited during their training sessions at various training grounds in their areas.
Self-administered questionnaires were used to collect demographic profiles and the presence of AKP and extrinsic risk factors, as described in the previous study. [7]emographic data included gender, age, running experience, and height and weight to calculate their body mass index (BMI).A standardised AKP questionnaire by Kujala and colleagues was utilised to determine the prevalence of AKP.It consisted of 13 short questions about the participant's knee symptoms and functional limitations associated with AKP. [9]he tool has a maximum score of 100 which was used to rate all participants' AKP symptoms.A cut-off score of 83 identified participants with AKP as recommended by Kujala and colleagues.This standardised AKP questionnaire has good test-retest reliability and high validity (ICC = 0.92). [9,10]he extrinsic risk factor questionnaire was developed by using the current literature available.It was reviewed by five independent experts for content validity.The reviewers included local senior clinicians and researchers in the field of musculoskeletal injuries.Following the review process, a pilot study was conducted among the same population (10% of the sample size) to check its validity.No changes or revisions were made to the questionnaire after the pilot study.
This study obtained ethical clearance from the biomedical research ethics committee of the University of KwaZulu-Natal (BFC377/15).Before the data were collected, all participants were given leaflets providing details about the study and they were requested to complete consent forms once they agreed to participate in the study.Consent was obtained from parents/guardians of participants younger than 18 years.During the data collection, the first author hand-delivered the questionnaires to the participants during their training sessions and collected them immediately after completion.
Data were captured using Microsoft Excel first and later imported into SPSS for analysis.Descriptive statistics included the calculation of frequencies and percentages for single variables.Inferential statistics included the calculation of the chi-square to determine the association between variables.Logistic regression analysis was done to describe data and explain the relationship between AKP and various independent variables (risk factors).The level of significance was set at p ≤ 0.05.

Discussion
This study described the a higher prevalence of AKP among this population of runners compared to the global prevalence which is between 15-45% according to Cook el al. [1] Young and inexperienced runners were more affected compared to the rest of the population.These results were found to be congruent with other studies. [1,11]The causes of AKP have been found to be multifactorial.This section will further discuss the extrinsic risk factors presented in the Results section above.Various factors were described in this study some of which contributed to AKP significantly.
Training load is one of the factors reported in the literature as a contributor to many sports-related injuries including AKP. [12] Both underloading and overloading can put a runner at risk of injuries and low performance.In this study, participants who trained two or more times a week were less likely to develop AKP compared to those who never trained or trained inadequately.This undertraining or lack of training contributed to many of the participants experiencing AKP during running races.According to a study by Nielson et al., runners who trained for competition regularly were found to be less likely to have running-related injuries than those who did not train. [12]Many injuries are as a result of muscle fatigue which may lead to muscle imbalances.Therefore, adequate training lowers muscle fatigue thresholds and allow a runner to perform better.Training load and fatigue should always be monitored and modified during training and competition so that injury risks can be lowered.
Overtraining syndrome is a common problem among athletes in general.It consists of "prolonged fatigue and underperformance, following a period of heavy training or competition, lasting at least two weeks." [13]As much as overtraining is a good technique to improve performance among athletes, it can lead to bodily harm and underperformance, putting strain on the body and supressing the immune system.This may lead to risks of injuries and illnesses.Therefore, it is important for runners to avoid overtraining when preparing for their running races.A runner's fitness levels, body composition, level of running, injury history and age should be considered when determining training loads.New runners tend to do too much too soon.They should rather consider to increase their training load gradually in order to avoid overuse injuries.
This study reported that many participants occasionally included warm-up and cool-down sessions during training and competition.However, warm-up and cool-down factors did not show any significant contribution to AKP.Warm-up is a lowlevel activity which prepares the body for vigorous activity.In