We analyze and compare the differences in the biomechanical parameters between the lead straight punch and the index of force development of the lower extremities of boxers of different levels of ability. This can bridge the technical gap and provide insight and information for training strategies and athlete selection. To this end, a synchronized Vicon infrared 3D motion-capture system, two Kistler force platforms, and Kistler 8 target sensors were used for analysis. Sixteen boxers were recruited and sorted into an elite group (height 181.14 ± 3.01 cm, body mass 76.00 ± 10.028 kg) and a junior group (179.67 ± 5.84 cm, body mass 75.47 ± 12.19 kg), and their lead straight punch was then compared and analyzed. Three punch velocity indexes—peak velocity, contact velocity and Punching deceleration rate—six strength indexes—impulse, peak force, relative strength, peak time (frame), rate of force development (RFD), and movement time—and five exertion of both legs indexes— peak force, peak force/body mass, peak time, RFD index, and RFD/body mass index—were selected for analysis. Significant differences in the peak punch velocity and contact velocity were found between the two groups (7.162 ± 0.475 m•s⁻¹vs. 6.317 ± 0.415 m•s⁻¹, Cohen’s d = 1.89, p < 0.01, 5.557 ± 0.606 m•s⁻¹ vs. 4.874 ± 0.385 m•s⁻¹, Cohen’s d = 1.34, p < 0.05). Furthermore, significant differences were noted in the peak force [(1507.99 ± 411) N vs. (1035.45 ± 220) N, Cohen’s d = 1.43, p < 0.01], relative strength [(21.04 ± 5.88) N•kg⁻¹ vs. (15.61 ± 2.53) N•kg⁻¹, Cohen’s d = 1.19, p < 0.05], impulse [(88.61 ± 25.88) N•ms⁻¹ and (60.53 ± 9.03) N•ms⁻¹, Cohen’s d = 1.45, p < 0.05], and RFD [(88.61 ± 25.88) N•ms⁻¹ and (60.53 ± 9.03) N•ms⁻¹, Cohen’s d = 1.45, p < 0.05]. Among the four indexes of the lower extremities from two embedded Kistler force platforms, there were significant differences in the lead leg’s peak force/body mass [(19.68 ± 4.096) N•kg⁻¹vs. (13.320 ± 2.223) N•kg⁻¹, t = 3.902, Cohen’s d = 1.92, p < 0.01], RFD index [(16.90 ± 3.269) N•ms⁻¹vs. (10.28 ± 4.313) N•ms⁻¹, Cohen’s d = 1.72, p < 0.01], and RFD/body mass index [(23.47 ± 4.09%) N•ms⁻¹Kg⁻¹ vs. (15.38 ± 5.65%) N•ms⁻¹Kg⁻¹, Cohen’s d = 1.64, p < 0.01]. There were no significant differences in the four indexes on the rear leg between the two groups (p &gt; 0.05). Based on the disparity in the effect of the lead straight punch and the biomechanical parameters of both lower extremities, the boxers must attach importance to sequential acceleration-braking training to improve the terminal velocity of the hand, and thus improve the contact velocity. Furthermore, it is advised that coaches and practitioners carefully consider increasing start-up strength training of the lead leg and attempt to improve the peak velocity of the lead straight punch. In addition, these biomechanical parameters can be used as criteria for the selection of boxers.

Objective: To bridge the technical gaps in reserve athletes in China’s national boxing program and to rapidly improve the overall level of boxing, the Wushu Sports Administration Center of the General Administration of Sports of China has sent outstanding Sanda players to boxing events through cross-border talent transfer. This was done to widely improve the strengths and resources in various fields to prepare for the Tokyo Olympic Games. In view of this, we analyzed and compared differences in biomechanical parameters of the lead straight punch and index of force developments of the lower extremities between Sanda and boxing. The results provide information and insights to bridge the technical gaps in cross-border talent transfer from Sanda to boxing.Methods: We employed a Vicon infrared 3D motion capture system, two Kistler platforms, a Kistler target, and a synchronous instrument. Eleven boxers and sixteen Sanda athletes were recruited, and their lead straight punch techniques were compared and analyzed. Three indexes of punch velocity, six indexes of strength measurement, and four indexes of lower extremity strength were analyzed.Results: Significant differences in the peak punch velocity and contact velocity were found between the two groups. Furthermore, significant differences were noted in the peak impulse, peak strength, relative strength, and the rate of force development (RFD). Among the kinetics indexes of lower limbs, the front leg strength index was higher in the boxing group than in the Sanda group, namely the RFD index and RFD/body mass.Conclusion: Based on the disparity in the effects of the lead straight punch and biomechanical parameters of both lower extremities, we can conclude that, compared to the boxers, most Sanda athletes lack standard punching technique. Therefore, it is advised that coaches and practitioners carefully consider selecting Sanda athletes with higher technical standards of punching.

This study aimed to investigate the functional roles and fatigue effects of the striking and supporting legs in consecutive stationary side-kick techniques among Sanda fighters. By analyzing muscle activation (root mean square, RMS), this study provides insights for targeted muscle training in Sanda. Surface electromyography (sEMG) was utilized to collect data from 10 Chinese elite-level Sanda athletes (height: 178.5 ± 4.3 cm, weight: 72.1 ± 5.6 kg, training experience: 7.8 ± 1.9 years; 4 international master athletes, 6 national master athletes) performing continuous static side-kick techniques. Vicon synchronization equipment was used to determine the start and end points of the movement. Thirty seconds of raw sEMG data were preprocessed and segmented into 1-second intervals. A sliding window approach with feature averaging was employed to calculate the root mean square (RMS) values for 50-millisecond windows, followed by the computation of mean RMS values per 1-second interval. The fatigue characteristics of major muscle groups in the lower limbs (kicking leg and supporting leg) were evaluated by analyzing the mean RMS values across different phases over time: the initial phase (1–5 s), the middle phase (initial: 1–5 s, middle: 15–19 s, final: 26–30 s). Regarding fatigue accumulation, elite Chinese Sanda fighters exhibited significant RMS reductions in the striking leg’s primary muscle groups (gastrocnemius, vastus medialis, and gluteus maximus) over time (change rates: -5.29% to -7.50%, p < 0.01), indicating pronounced fatigue. In contrast, the supporting leg’s major muscle groups showed stable RMS changes (change rates: -3.52% to -3.97%, p > 0.05), suggesting minimal fatigue accumulation during the task. For muscle activation, the RMS values of the striking leg’s primary muscles were significantly higher than those of the supporting leg (p < 0.01). The tibialis anterior in the supporting leg exhibited greater activation compared to the striking leg (p < 0.05), while hamstring activation showed no significant difference between legs (p > 0.05). Correlation analysis revealed that the striking leg’s force production is driven by synergistic activity among the vastus medialis, rectus femoris, vastus lateralis, and gluteus maximus (r = 0.74 ~ 0.78, p = 0.007 ~ 0.014), highlighting their critical role in hip and knee joint force generation. In contrast, the supporting leg relied on a strong correlation between the gastrocnemius and tibialis anterior (r = 0.81, p < 0.01) for ankle joint stability and a moderate correlation between the gluteus maximus and gluteus medius (r = 0.65, p < 0.05) for hip balance, underscoring distinct muscle coordination patterns between the two legs. In Chinese elite Sanda fighters performing continuous in-place side-kick movements, the striking leg’s power-generating muscle groups—primarily the quadriceps and gluteus maximus—exhibit significant fatigue. Meanwhile, the supporting leg maintains stability through the tibialis anterior and gastrocnemius. These findings highlight potential strength asymmetries that could signal fatigue onset or even injury risk, offering valuable insights for coaching strategies and rehabilitation protocols. Training recommendations include plyometric exercises to enhance the explosive power of the quadriceps and gluteus maximus, resistance training to improve the endurance of the striking leg, and isokinetic training to strengthen the stability of the tibialis anterior and gastrocnemius in the supporting leg, thereby further optimizing the training regimen.

Purpose: This study investigated the topological organization of brain networks in Sanda athletes across different training levels to elucidate the neural mechanisms underlying the sport’s exceptional sensorimotor integration and training-related neural plasticity. Methods: Multimodal magnetic resonance imaging (MRI) data were collected from 35 participants, including elite athletes, second-level athletes, and novices. Using the Automated Anatomical Labeling 116-region atlas (AAL116), structural connectivity (SC) networks were constructed based on fractional anisotropy (FA) derived from diffusion tensor imaging, while functional connectivity (FC) networks were computed using Pearson correlations between regional blood-oxygen-level-dependent (BOLD) time series. Structure–function coupling (SFC) networks were generated as a weighted linear combination of SC and FC. Network differences were assessed using Network-Based Statistic (NBS) and graph-theoretical analyses. Results: Elite athletes exhibited prominent structure–function coupling within visual–motor–executive pathways, whereas novices showed greater involvement of language–rhythm-related pathways. At the global level, elite athletes demonstrated stronger small-world organization and network synchrony, suggesting more efficient information transmission. At the nodal level, the parietal–cerebellar system emerged as a critical hub across the examined networks, with particularly prominent involvement of the right supramarginal gyrus (SMG.R) and right cerebellar lobule VI (CRBL6.R). Discussion: These regions are likely to play a central role in sensorimotor integration and rhythm control. These findings confirm that long-term Sanda training optimizes brain network topology, providing key insights into the neural plasticity of athletic expertise.