The immediate effect of long-axis talocrural manipulation and sham laser on sagittal motion of the ankle joint and bowling speed of club cricket pace bowlers in the eThekwini Municipality

Abstract

Purpose: The purpose of this study was to determine the immediate effect of talocrural long-axis manipulation and sham laser on sagittal ankle motion and bowling speed in club cricket pace bowlers in the eThekwini Municipality. Method: Fifty-four club-level pace bowlers were randomly assigned into two equal groups, Groups A and B (n = 27 each). Participants in Group A received a talocrural long-axis manipulation (TLAM) intervention, while participants in Group B received a sham laser intervention (placebo). All participants bowled six maximum-effort deliveries both before and after the intervention. Bowling speed (km·h⁻¹) was measured using a SpeedTrac X Radar Gun (EMG Companies Inc., Prescott, USA). Both front and back foot ankle sagittal range of motion (ROM) (°), namely, dorsiflexion and plantarflexion, were assessed using an analogue goniometer (Hitech Therapy, Durban, South Africa). For each participant, the mean of the three fastest deliveries was recorded for the pre- and post-intervention. Data were analysed using SPSS version 31. Paired sample t-tests were used to compare pre- and post-intervention means for ankle sagittal motion and bowling speed to determine statistical significance. To evaluate the collective influence of the intervention type (Group A: talocrural manipulation; Group B: sham laser) on changes in ankle joint ROM and bowling speed, with age as a covariate, a GLM multivariate analysis was conducted. A follow-up univariate ANOVA test was performed to determine which individual variables contributed to the overall intervention effect. The correlation between the ankle sagittal ROM and bowling speed was assessed using Spearman’s correlation. An alpha level of 0.05 was set to determine statistical significance; therefore, a p-value of <0.05 was considered statistically significant. Results: The mean ± standard deviation (SD) of the age of participants was 31.7 ± 8.0 years in Group A (intervention) and 32.8 ± 7.4 years in Group B (control). In the intervention group, front foot dorsiflexion improved significantly from 110.9° ± 5.7 to 101.9° ± 7.7 (-9.0°, 95% CI: −11.6 to −6.4, p < 0.001), and plantarflexion improved significantly from 152.9° ± 9.1 to 160.0° ± 7.3 (+7.1°, 95% CI: 4.5 to 9.9, p = 0.001). A smaller but significant improvement was also observed in back foot plantarflexion from 154.1° ± 8.2 to 155.8° ± 7 (+1.7°, 95% CI: 0.2 to 3.1, p = 0.025), with an insignificant improvement in back foot dorsiflexion (-1.3°, 95% CI: −3.3 to 0.6, p = 0.173). In contrast, no significant changes in front foot or back foot ROM were observed in the control group. Bowling speed in Group A increased significantly from 112.8 ± 12.5km·h⁻¹ to 118 ± 11.3km·h⁻¹ (+5.4km·h⁻¹, 95% CI: 2.6 to 8.3, p < 0.001). In contrast, no significant change in bowling speed was observed in Group B. A multivariate analysis confirmed that the intervention had a significant collective effect on ankle sagittal ROM and bowling speed (Pillai’s Trace = 0.488, F (5,47) = 9.0, p < 0.001, partial η² = 0.50), independent of age. A statistically significant, moderate negative correlation (r = -0.484, p = 0.049) was observed between increases in ankle dorsiflexion ROM and bowling speed in the intervention group. Conclusion: TLAM of the front foot resulted in a significant increase in ankle sagittal ROM and bowling speed in club-level cricket pace bowlers, with no adverse effects reported. This provides the first evidence that front foot ankle manipulation can improve a key performance metric in pace bowling, reinforcing the ankle’s crucial biomechanical role in generating bowling speed. These findings suggest that TLAM could support the performance enhancement of pace bowlers, offering a safe and non-invasive intervention that manual therapists can use within a cricket team. While improvements in ankle sagittal motion and bowling speed were observed, the effect of TLAM on other pace bowling performance metrics, such as accuracy and bounce, remains unexplored. Future research should explore these performance metrics, assess the combined impact of TLAM with upper body manipulation, and investigate the effect of TLAM in different population groups, such as female pace bowlers.