Lower-limb joint kinetics in jump rope skills performed by competitive athletes

Effects of shoe bending stiffness on the coordination variability of lower extremities in alternating jump rope skipping

This study aimed to investigate how different longitudinal bending stiffness (LBS) in jump rope shoes affect the coordination variability of lower extremity segments and athletic performance during alternating jump rope skipping (AJRS). Thirty-two elite male athletes performed 30-s AJRS tasks wearing shoes with LBS measured at 3.1 Nm/rad (no-carbon-fibre-plate jump rope shoes, NS), 5.1 Nm/rad (low-stiffness-carbon-fibre-plate jump rope shoes, LS) and 7.6 Nm/rad (high-stiffness-carbon-fibre-plate jump rope shoes, HS). Motion capture tracked lower extremity kinematics. The HS shoes exhibited a more ground contacts in the first stage (p < 0.05) and a shorter average ground contact time (p < 0.05). The HS exhibited a smaller metatarsophalangeal joint (MTPJ) extension angle during 30-44% of the stance phase (p < 0.05), smaller MARP (mean absolute relative phase) of the MTPJ-ankle segments (p < 0.001) and smaller CRP (continuous relative phase) during 24-45% of the stance phase (p < 0.05). Coordination variability of the MTPJ-ankle segments was negatively correlated with the number of ground contacts during AJRS (p < 0.01, adjust R2 = 0.192). HS could provide enhanced stability by reducing coordination variability and enhance performance during the first stage in ARJS. These findings could provide insights for guiding future research and development in jump rope shoe design.

Effects of Barefoot and Shod Conditions on the Kinematics and Kinetics of the Lower Extremities in Alternating Jump Rope Skipping-A One-Dimensional Statistical Parameter Mapping Study

PURPOSE

To explore the difference in the biomechanics of the lower extremity during alternating jump rope skipping (AJRS) under barefoot and shod conditions.

METHODS

Fourteen experienced AJRS participants were randomly assigned to wear jump rope shoes or be barefoot (BF) during the AJRS at a self-selected speed. The Qualisys motion capture system and Kistler force platform were used to synchronously collect the ground reaction forces and trajectory data of the hip, knee, ankle, and metatarsophalangeal (MTP) joints. One-dimensional statistical parameter mapping was used to analyze the kinematics and kinetics of the lower extremity under both conditions using paired t-tests.

RESULTS

Wearing shoes resulted in a significant decrease in the ROM (p < 0.001) and peak angular velocity (p < 0.001) of the MTP joint during the landing phase. In addition, the MTP joint power (p < 0.001) was significantly larger under shod condition at 92-100% of the landing phase. Moreover, wearing shoes reduced the peak loading rate (p = 0.002).

CONCLUSION

The findings suggest that wearing shoes during AJRS could provide better propulsion during push-off by increasing the MTP plantarflexion joint power. In addition, our results emphasize the significance of the ankle and MTP joint by controlling the ankle and MTP joint angle.

Effects of Footwear Selection on Plantar Pressure and Neuromuscular Characteristics during Jump Rope Training

This study examined what footwear type influenced plantar pressure and lower extremity muscle activations in jump rope training. Ten healthy physical-education graduate students participated in this study. The biomechanical parameters during the jump rope training were collected by an AMTI force platform, a Novel Pedar-X insole and a wireless electromyography (EMG) system. The results of the force platform indicate that vertical ground reaction force (vGRF) and contact time were much higher in the one-leg landing (both p = 0.001). The GRF, GRF (BW) and Lat MF pressure were significantly greater in the one-leg landing (p = 0.018, 0.013 and 0.027); the pressure of the Lat MF and H area were significantly greater in the volleyball shoe (p = 0.025, 0.031); the pressure of the Mid FF and Lat FF area were significantly greater in the jumping shoe (p = 0.005, 0.042). No significant difference in EMG was found between footwear and landing conditions. In summary, the running shoe and jumping shoe might be a better choice for people who exercise. However, the running shoe is recommended for people when both jumping and running are required.

Plasma Metabolomics Reveals β-Glucan Improves Muscle Strength and Exercise Capacity in Athletes

The present study aimed to assess the changes in muscle strength and plasma metabolites in athletes with β-glucan supplementation. A total of 29 athletes who met the inclusion criteria were recruited for this study (ChiCTR2200058091) and were randomly divided into a placebo group (n = 14) and β-glucan group (n = 15). During the trial, the experimental group received β-glucan supplementation (2 g/d β-glucan) for 4 weeks and the control group received an equal dose of placebo supplementation (0 g/d β-glucan), with both groups maintaining their regular diet and exercise habits during the trial. The athletes’ exercise performance, muscle strength, and plasma metabolome changes were analyzed after 4 weeks of β-glucan supplementation. The results showed a significant increase in mean grip strength (kg), right hand grip strength (kg), left triceps strength (kg), and upper limb muscle mass (kg) in the experimental group after the 4-week intervention compared to the preintervention period (p < 0.05). A comparison of the difference between the two groups after the intervention showed that there were significant differences between the control group and the experimental group in mean grip strength (kg) and right-hand grip strength (kg) (p < 0.05). Athletes in the experimental group showed significant improvements in 1 min double rocking jump (pcs), VO2max (ml/kg-min) (p < 0.05). The β-glucan intake increased the creatine-related pathway metabolites in plasma. Overall, these results suggest that 4 weeks of β-glucan supplementation can improve muscle strength in athletes, with the potential to increase aerobic endurance and enhance immune function, possibly by affecting creatine-related pathways.

The Effect of an 8-Week Rope Skipping Intervention on Standing Long Jump Performance

The purpose of this study was to explore the utility of an 8-week rope skipping intervention in enhancing standing long jump performance was assessed by means of specific kinematic parameters acquired by 3-D space photography. The fifteen male college students from the physical education institute were randomly recruited as the research subjects. Participants first completed a standing long jump test without rope skipping intervention. Participants subsequently took part in a second standing long jump test after rope skipping training. Two high-speed digital cameras with 100 Hz sampling rate were synchronized to capture the movement. The captured images were processed using motion analysis suite, and the markers attached to joints on images were optical auto capture. Based on the results, the velocity of the center of gravity at take-off and landing were significantly improved. In addition, the study confirmed the requirement for forward tilt of the hip joint at landing to increase the velocity of the center of gravity and hence long jump distance. The detailed kinematic analysis described here provided further evidence of the benefits of integrating non-specialized and specialized training activities to enhance athletic performance and offers a contribution to movement theory and practice.

The Influence of Different Rope Jumping Methods on Adolescents' Lower Limb Biomechanics during the Ground-Contact Phase

As a simple and beneficial way of exercise, rope skipping is favored by the majority of teenagers, but incorrect rope skipping may lead to the risk of injury. In this study, 16 male adolescent subjects were tested for bounced jump skipping and alternating jump rope skipping. The kinematic data of the hip, knee, ankle and metatarsophalangeal joint of lower extremities and the kinetics data of lower extremity touching the ground during rope skipping were collected, respectively. Moreover, the electromyography (EMG) data of multiple muscles of the lower extremity were collected by Delsys wireless surface EMG tester. Results revealed that bounced jump (BJ) depicted a significantly smaller vertical ground reaction force (VGRF) than alternate jump (AJ) during the 11−82% of the ground-contact stage (p < 0.001), and the peak ground reaction force and average loading rate were significantly smaller than AJ. From the kinematic perspective, in the sagittal plane, when using BJ, the flexion angle of the hip joint was comparably larger at 12−76% of the ground-contact stage (p < 0.01) and the flexion angle of the knee joint was significantly larger at 13−72% of the ground-contact stage (p < 0.001). When using two rope skipping methods, the minimum dorsal extension angle of the metatarsophalangeal joint was more than 25°, and the maximum was even higher than 50°. In the frontal plane, when using AJ, the valgus angle of the knee joint was significantly larger during the whole ground-contact stage (p < 0.001), and the adduction angle of the metatarsophalangeal joint (MPJ) was significantly larger at 0−97% of the ground-contact stage (p = 0.001). EMG data showed that the standardized value of root mean square amplitude of the tibialis anterior and gastrocnemius lateral head of BJ was significantly higher than AJ. At the same time, that of semitendinosus and iliopsoas muscle was significantly lower. According to the above results, compared with AJ, teenagers receive less GRF and have a better landing buffer strategy to reduce load, and have less risk of injury during BJ. In addition, in BJ rope skipping, the lower limbs are more inclined to the calf muscle group force, while AJ is more inclined to the thigh muscle group force. We also found that in using two ways of rope skipping, the extreme metatarsophalangeal joint back extension angle could be a potential risk of injury for rope skipping.

Effects of Jump-Rope-Specific Footwear Selection on Lower Extremity Biomechanics

Footwear is among the most important equipment in sports to decrease injuries and enhance performance during exercise. In this study, we investigated differences in lower extremity plantar pressure and muscle activations during jump rope activities. Ten participants performed jump rope under two landing conditions with different footwear. A force platform (AMTI, 1000 Hz), a Novel Pedar-X system (Nove, 100 Hz), and a wireless electromyography (EMG) system (Noraxon, 1500 Hz) were used to measure biomechanical parameters during the jump rope exercise. Vertical ground reaction forces (vGRF), plantar pressure, and lower extremity muscle activations were analyzed. One-leg landing resulted in a significantly greater vGRF and shorter fly time than two-leg landing (p < 0.05). A significantly higher peak pressure and lesser toe (LT) area pressure was shown with the jumping shoe (all p < 0.05), but lower plantar pressure resulted in the middle foot area (p < 0.05). The EMG results of tibialis anterior (TA) were significantly greater with one-leg landing (all p < 0.05) during the pre- and background activity (BGA) phases. The results suggest that plantar pressure distribution should be considered when deciding on footwear during jump rope exercises, but care should be taken with regards to recovery after repeated collisions and fatigue. The jumping shoe provides benefits in terms of decreased plantar pressure sustained during jump rope exercises.

Speed Rope Skipping - Performance and Coordination in a Four-Limb Task

This study investigated biomechanical characteristics of Speed Rope Skipping (RS) and estimated the contribution of the lower and upper limbs to overall performance. Lower (jumping), upper (turning), and whole-body (skipping) performance were examined in 23 rope skippers. All tests were recorded by 2 D video and nine skipping tests were performed in a 3 D motion capture system. Similar movement patterns were observed for the lower limbs in all participants, while handle trajectories differed in shape and symmetry according to performance. In general, turning unlike jumping performance was close to and significantly correlated with skipping performance. Therefore, it appears that lower extremity movement may be adapted to the limiting capacity of the upper extremity to maintain movement stability.

Movement Coordination during Forward and Backward Rope Jumping: A Relative Phase Study

Rope jumping is a popular training method in athletic programs, fitness, and physical education. Forward and backward rope jumping has been used for evaluating athlete's performance. Both of these two jumps require coordination in the upper and lower limbs. However, no study has focused on movement coordination during forward and backward rope jumping. Relative phase (RP) analysis was widely known as an innovative method for evaluating human movement coordination. Thus we aimed to investigate the movement coordination during forward and backward rope jumping by using RP analysis. 78 elementary and junior high school students participated in this study. 30 seconds rope jumping was recorded for both forward and backward by using iPhone video. Pose estimation software was used for jump motion tacking. Movement coordination was analyzed through RP analysis, absolute maximum value, mean absolute RP, and deviation phase were calculated for evaluating movement coordination, the trend of in or out-of-phase, as well as movement stability. As a result, 3994 forward and 3961 backward jumps were analyzed. There was a significant difference in movement coordination between forward and backward rope jumping. Compared to forward, backward jumps showed worse movement coordination, a trend to be out-of-phase, and less stability. It was the first time that movement coordination during rope jumping was studied. We considered that further research on coordination during rope jumping can provide new insight into athlete performance management, fitness guidance, and physical education.