Six-Week Remodeled Bike Pedal Training Improves Dynamic Control of Lateral Shuffling in Athletes With Functional Ankle Instability

BACKGROUND

Remodeled bicycle pedal training with multidirectional challenges through muscle strengthening and neuromuscular facilitation may increase dynamic postural control and performance during lateral shuffling for athletes with functional ankle instability (FAI).

HYPOTHESIS

The 6-week remodeled bicycle pedal training is effective on the ankle joint control and muscle activation, and especially that of the ankle evertor muscle co-contraction to improve dynamic postural control during lateral shuffling for athletes with FAI.

STUDY DESIGN

Laboratory randomized controlled trial.

LEVEL OF EVIDENCE

Level 2.

METHODS

Fourteen healthy athletes (healthy group) and 26 athletes with FAI aged 18 to 30 years were included in the study. The athletes with FAI were randomly assigned to either the training group (FAI-T group) or the nontraining group (FAI-NT group). The athletes in the FAI-T group underwent 6 weeks of remodeled bicycle pedal training, whereas those in the FAI-NT group did not undergo any intervention. Muscle co-contraction index and muscle activation in the initial contact (IC) and propulsion phases, and ankle joint angle in the IC and propulsion phases were measured during lateral shuffling before and after 6 weeks of training.

RESULTS

After remodeled bicycle pedal training, the FAI-T group demonstrated greater muscle activation in the hamstring (P = 0.01), greater muscle coactivation of the tibialis anterior (TA) and the peroneus longus (P = 0.01), and greater ankle eversion angle in the IC phase. Significantly greater muscle activation of the TA (P = 0.01), greater coactivation of quadriceps and hamstring (P = 0.03), and a smaller ankle inversion angle (P = 0.04) in the propulsion phase were observed in the FAI-T group after training compared with those in the FAI-NT group.

CONCLUSION

Remodeled bicycle pedal training facilitates the TA and peroneus longus activation and the coactivation of the quadriceps and hamstring muscles during lateral shuffling and resulted in enhanced ankle and knee joint stability. In addition, a better ankle movement strategy during a dynamic task can be achieved via a 6-week remodeled pedal training program.

CLINICAL RELEVANCE

This remodeled bicycle pedal training can be effective for rehabilitating athletes with FAI to recover lateral dynamic movement capability.

The Submaximal Lateral Shuffle Test: A reliability and sensitivity analysis

Lateral ankle stability and how it changes in different footwear has been investigated for years. Research, however, has shown a lack of reliability or sensitivity of available methodologies. This study aimed to evaluate the test-retest reliability and sensitivity of a novel lateral stability protocol, the Submaximal Lateral Shuffle Test (SLST). We recruited 11 and 40 participants to assess reliability and sensitivity of the SLST, respectively. Participants performed the SLST in footwear that differed in collar height and upper stiffness. ICC values showed good to excellent reliability in peak ankle angles and moments, ground reaction forces, impulses, stance time, and performance time. Significantly lower peak inversion and adduction angles and lower medio-lateral push off peak forces were found in the high cut shoes compared to the low cut shoes. The medio-lateral landing peak force showed lower forces in the high cut shoes. The smallest worthwhile change indicated meaningful differences in 70.0-82.5% of participants for inversion, adduction, medio-lateral landing peak, and push off peak forces. These results, however, were not systematic such that there was not a consistent direction of the difference for all participants. In conclusion, the SLST is a promising protocol to further investigate lateral stability in footwear.

Reliability of Three Timing Systems Used to Time Short on Ice-Skating Sprints in Ice Hockey Players

Bond, CW, Willaert, EM, Rudningen, KE, and Noonan, BC. Reliability of three timing systems used to time short on ice-skating sprints in ice hockey players. J Strength Cond Res 31(12): 3279-3286, 2017-Speed and acceleration are highly valued in ice hockey and frequently assessed using timing systems. Coaches must use reliable timing systems to assess these attributes, but many systems have not been thoroughly evaluated and the required number of sprint repetitions to obtain the coach's desired degree of reliability for a system may be impractical. This study aimed to compare the reliability of a single photocell (PC), a single laser with a microprocessor (LA), and a digital video camera (VC); and in doing so, evaluate the influence of completing additional sprint repetitions on each systems' reliability. We hypothesized that PC and LA would yield different times, have inferior reliability, and require a larger number of sprint repetitions to obtain the same degree of reliability compared with VC. Seventeen male ice hockey players completed 5 repetitions of a 9.15 m on ice-skating sprint timed simultaneously by PC, LA, and VC. The times obtained from VC were narrowly distributed around the mean compared with PC and LA and resulted in a mean sprint time approximately 0.05 and 0.07 second faster than PC and LA, respectively {PC: 1.74 second (95% confidence interval [1.72-1.76]); LA: 1.76 second [1.74-1.78]; VC: 1.69 second [1.67-1.70]}. When 2 sprint repetitions were completed, PC and LA typical error (TE) and smallest worthwhile difference (SWD) were 2.8- and 4.3-fold greater than VC, respectively. As more repetitions were completed, TE and SWD for PC and LA improved but remained approximately 2-fold greater than VC even when 5 repetitions were completed. With a smaller TE and SWD, VC was able to detect smaller "real" changes in a player's sprint performance over time compared with PC and LA.

Influence of gait mode and body orientation on following a walking avatar

Regulating distance with a moving object or person is a key component of human movement and of skillful interpersonal coordination. The current set of experiments aimed to assess the role of gait mode and body orientation on distance regulation using a cyclical locomotor tracking task in which participants followed a virtual leader. In the first experiment, participants moved in the backward-forward direction while the body orientation of the virtual leader was manipulated (i.e., facing towards, or away from the follower), hence imposing an incongruence in gait mode between leader and follower. Distance regulation was spatially less accurate when followers walked backwards. Additionally, a clear trade-off was found between spatial leader-follower accuracy and temporal synchrony. Any perceptual effects were overshadowed by the effect of one's gait mode. In the second experiment we examined lateral following. The results suggested that lateral following was also constrained strongly by perceptual information presented by the leader. Together, these findings demonstrated how locomotor tracking depends on gait mode, but also on the body orientation of whoever is being followed.