Sagittal spinal alignment in long-term surfers of eThekwini

Abstract

Background: Sagittal spinal alignment and posture deteriorate with age, but may be affected by physical activity. Surfers catch and ride breaking waves using a surfboard, which they paddle while prone with their spine extended. Spinal extension exercise is generally beneficial to postural development with age. This study aimed to investigate whether an association exists between long-term surfing and the progression of sagittal spinal alignment and posture i.e. cervical lordosis (C-angle (flex and Cobb)), thoracic kyphosis (T-angle (flex and Cobb)), lumbar lordosis (Langle (flex and Cobb)), and sagittal posture (Posture Number) in ostensibly healthy males over the age of 50. The objectives of this study included: 1) Assessing the. C, T, L-angles, and Posture Numbers in long-term male surfers and physically active non-surfer ; 2) Determining whether any significant differences exist between the selected sagittal spinal alignment and posture parameters within or between the surfing and non-surfing groups; and 3) Determining the association, if any, between age, years of surfing and selected spinal alignment parameters. Methodology: 52 males over the age of 50 underwent a case history and postural examination. Their C, T, and L-angles were plotted onto graph paper to analyse using BiomechFlex. Anterior and lateral full-body photographs were taken to analyse using Posture Pro version 8. The generated statistics were analysed using STATA version 16. The summary measures used included the mean, median, standard deviation, range and percentiles of spinal angle and posture variables, as well as the age, anthropometric variables, activity hours per week and activity years. Results: The mean body mass index (BMI) of the S group (24.9kg/m²) was significantly lower than the 27.6kg/m² mean of the NS group, p=0.00. The average time spent on activities per week was over 3 hours in both groups (S group - 3.28hrs and NS groups - 4.67hrs, p=0.0004). On average, the S group (45.6 years) had been practising surfing for significantly more years than the NS group (32 years) had been practising their respective primary activities, p=0.0008. There were no significant differences between the S and NS groups in terms of C- (flex p=0.6234), T- (flex p=0.5758 and Cobb p= 0.5518), or L-angles (flex p=0.6171 and Cobb p=0.6142), or Posture Number (p=0.5348). The T-angles (flex and Cobb) obtained from both NS and S groups were greater than 40⁰, which is classified as hyperkyphotic. There was a positive correlation between age and Posture Number in the S group (r = 0.4307 and p-value = 0.0316), but not the NS group. There was a significant association between Posture Number and T-angle (flex p=0.027 and Cobb p=0.026). The NS group had a 2.15⁰ (flex) and 2.09⁰ (Cobb) greater T-angles for any given posture Number. The NS group had an average of 2.9⁰ (flex) and 2.23⁰ (Cobb) lower Langles than the S group for any given BMI. Thus, surfing may suggest benefit of surfing to sagittal spinal alignment and posture. Conclusion: The results of this study show that long-term surfing is beneficial to the aging individual in terms of body composition. However, it is no more effective at mediating the effect of age on sagittal spinal alignment and posture than other forms of physical activity included in this study. Nevertheless, slight differences between the NS and S groups were present, which may indicate that the biomechanical or even postural effects/adaptations of long-term surfing differ from those of other activities. These subtle differences indicate the need for further research around physical activity, sagittal spinal alignment and posture.