Manifestations of Proprioception During Vertical Jumps to Specific Heights

Distinct Coordination Strategies Associated with the Drop Vertical Jump Task

INTRODUCTION

Coordination of multiple degrees of freedom in the performance of dynamic and complex motor tasks presents a challenging neuromuscular control problem. Experiments have inferred that humans exhibit self-organized, preferred coordination patterns, which emerge due to actor and task constraints on performance. The purpose of this study was to determine if the set of effective coordination strategies that exist for a task centers on a small number of robust, invariant patterns of behavior.

METHODS

Kinetic movement patterns computed from a cohort of 780 primarily female adolescent athletes performing a drop vertical jump (DVJ) task were analyzed to discover distinct groups into which individuals could be classified based on the similarity of movement coordination solutions.

RESULTS

Clustering of reduced-dimension joint moment of force time series revealed three very distinct, precisely delineated movement profiles that persisted across trials, and which exhibited different functional performance outcomes, despite no other apparent group differences. The same analysis was also performed on a different task-a single-leg drop landing-which also produced distinct movement profiles; however, the three DVJ profiles did not translate to this task as group assignment was inconsistent between these two tasks.

CONCLUSION

The task demands of the DVJ and single-leg drop-successful landing, reversal of downward momentum, and, in the case of the DVJ, vertical propulsion toward a maximally positioned target-constrain movement performance such that only a few successful outcomes emerge. Discovery of the observed strategies in the context of associated task constraints may help our understanding of how injury risk movement patterns emerge during specific tasks, as well as how the natural dynamics of the system may be exploited to improve these patterns.

Effects of 2 Different External Loads on Joint Position Sense and the Relationship Between Muscle Strength and Force Sense

CONTEXT

Joint position sense (JPS) tests of proprioception lack ecological validity because the testing conditions are so different from the normal function that they can contribute little to understanding the role proprioception plays in daily and sporting activities.

OBJECTIVE

To evaluate the effect of low and high external load on the knee JPS and to investigate the relationship between maximum voluntary isometric contraction and force sense (FS).

DESIGN

Experimental study.

SETTING

Research laboratory.

PARTICIPANTS

A total of 47 volunteers with no history of knee pathology.

INTERVENTIONS

Three active JPS tests performed with no load, low load, and high load were compared at the 45° target angle. For isometric FS test, 50% load was used. For isotonic low load and high load JPS tests, 30% and 70% loads were applied, respectively.

MAIN OUTCOME MEASURES

To analyze obtained data set 2-way multiple analysis of variance, repeated measures of analysis of variance, paired sample t test, and the Pearson correlation coefficient were used.

RESULTS

JPS was not affected by gender (male and female) and activity levels (sedentary, recreational, and trained). Results of the repeated measure of analysis of variance demonstrated the significant main effect of loads (P = .001). Significant differences were found between no load, low load, and high load JPS (P = .001). A positive and significant correlation was found between maximum voluntary isometric contraction and FS error values (r = .41, P = .001).

CONCLUSIONS

The results suggest that as the load level increases, the knee JPS improves. Knee JPS assessed under external load may be a more appropriate alternative to the nature of the sport. Those with higher muscle strength have a worse FS.

Short-term and long-term effects of ankle joint taping and bandaging on balance, proprioception and vertical jump among volleyball players with chronic ankle instability

OBJECTIVE

This study hypothesized that the prolonged use of taping during athletic activities produces more significant increases in proprioception, balance, and vertical jump among volleyball players with CAI.

DESIGN

A randomized controlled study.

PARTICIPANTS

One-hundred participants with chronic ankle instability (CAI) participated in this study. Participants were distributed into 3-groups: taping group, bandaging group, and control group.

PRIMARY OUTCOME MEASURES

Proprioception (ankle range of motion absolute error), balance(Y-balance test), and vertical jump (vertical jump tester).

INTERVENTIONS

Three interventions were performed: ankle rigid taping, ankle bandaging, and placebo taping. The measurements were performed at baseline, immediately, 2-weeks and 2-months after support.

RESULTS

Immediately after supports, there were non-significant differences between all groups for proprioception, balance (P < .05). There was a significant difference between banding and control groups, and taping and control groups for the vertical jump (P < .05). After 2-weeks and 2-months, there were significant differences between bandaging and control groups, and taping and control groups for proprioception, balance, and vertical jump (P < .05). There were non-significant differences between taping and bandaging groups (P < .05) during all assessments.

CONCLUSION

This study indicated that ankle taping and bandaging immediately improve vertical jump only; while they improve proprioception, balance, and vertical jump after 2-weeks and 2-months.

Joint- and subject-specific strategies in male basketball players across a range of countermovement jump heights

The purpose of this study was to investigate subject- and joint-specific strategies used by male basketball players as they increase their countermovement jump (CMJ) height from sub-maximal to maximal efforts. Lower extremity joint kinematics and kinetics were recorded as 11 male, NCAA Division I basketball players performed 8-10 CMJ across effort levels of approximately 25%, 50%, 75% and 100%. Simple correlation models were used to investigate the associations between effort levels (i.e., CMJ height) and joint mechanics (i.e., negative (eccentric) and positive (concentric) mechanical work performed at the hip, knee, and ankle joints) for each individual player and the entire group. Group-analyses showed that increases in all joint mechanical variables were associated with increases in CMJ height. In contrast, single-subject analyses revealed that players used individualised strategies, and selectively scaled the magnitude of mechanical work at none (n = 2), one (n = 2), two (n = 5), or all three (n = 2) joints as they increased CMJ efforts. In addition, individual players also appeared to selectively scale different combinations of eccentric or concentric joint work as they increased CMJ height. These results highlight that male basketball players use joint-specific strategies to increase CMJ height when progressively increasing CMJ effort.

A Review of Countermovement and Squat Jump Testing Methods in the Context of Public Health Examination in Adolescence: Reliability and Feasibility of Current Testing Procedures

BACKGROUND

In the context of a public health physical fitness (PF) examination in adolescence, a countermovement jump (CMJ) and a squat jump (SJ) are two vertical jump (VJ) tests widely used to evaluate lower limb muscle strength and power, respectively. The main criticism of both the CMJ and SJ test is the lack of test standardization. Therefore, the objectives of this review are: (a) to gather information about both jumps; (b) to investigate whether it is possible to identify common procedures referred to in the CMJ and SJ technical execution, and (c) to design standard operating procedures (SOPs) to promote CMJ and SJ standardization in an adolescent population aged 12-18 years.

METHODS

The review partially adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). Due to growing attention in monitoring physical health through field tests in recent years, articles were collected using the PubMed, Web of Science, and Scopus databases from January 2009 to July 2019. Original articles in which CMJ or SJ were used to assess the muscular strength in adolescents were eligible for further analysis. Articles written in English was imposed as a limit.

RESULTS

A total of 117 studies met the inclusion criteria. The description of the CMJ and SJ test procedures was different within the literature, with discrepancies in the jump technique, number of jumps, and measurement devices used.

CONCLUSIONS

A lack of method standardization for both the CMJ and the SJ test was identified. Based on the literature, SOPs for both VJs were proposed. These are useful in the context of public health PF examination in adolescents, as they facilitate an unbiased comparison of jump performance data between published studies.

Effect of Force Sense to Active Joint Position Sense and Relationships between Active Joint Position Sense, Force Sense, Jumping and Muscle Strength

We aimed to investigate the effect of external load on the joint position sense (JPS) accuracy and its relation to the target jump height. The present study also aimed to explore the relationship between force sense (FS) and maximum voluntary isometric contraction (MVIC). Participants' MVIC levels were determined during the 45-degree knee extension task. Then, participants were asked to execute a knee JPS task with external load (EL-JPS) and with no-load (EL-JPS). To assess jumping accuracy participants were instructed to jump with their 50% of maximum jump height. Results indicated that EL-JPS error values were lower than NL-JPS. EL-JPS was correlated to jumping errors. However, the relationship between NL-JPS and jumping errors was not significant. A significant correlation was found between MVIC and FS errors.

Effects of Reduced Effort on Mechanical Output Obtained From Maximum Vertical Jumps

The aim of this study was to evaluate the effect of reduced effort on maximum countermovement jumps. Groups of unskilled and skilled jumpers performed countermovement jumps without an arm swing at 100% and 50% effort. The results revealed markedly reduced jump height and work performed at 50% effort, although the maximum force and power output remained virtually unchanged. The observed differences were consistent across individuals with different jumping skills. A possible cause of differences in changes across the tested variables was a reduced countermovement depth associated with the 50% effort jumps. It is known to cause an increase in maximum force and power outputs, but not in jump height. Therefore, the jump height and work performed may be more closely related to our sense of effort when jumping, rather than our maximum force and power output. From a practical perspective, the present findings reiterate the importance of maximizing effort for making valid assessments of muscle mechanical capacities, as tested by maximal vertical jumps and, possibly, other maximum performance tasks.

Six weeks of multistation program on the knee proprioception and performance of futsal players

BACKGROUND

Proprioception and vertical jump are important parameters in the performance and prevention of injuries in futsal. However, very few studies have analyzed the role of multistation exercises to improve these variables. The purpose of this study was to assess the effects of a six-week multistation exercise program on knee joint position sense (JPS) and countermovement jump (CMJ) of futsal players.

METHODS

Thirty-four male futsal players randomly classified into experimental (N.=17) or control group (N.=17). The experimental group included a multistation exercise protocol to their training routines (2 times/week - 6 weeks); the control group continued their training routines. All the players completed similar training routines outside of the multistation exercises. Before (baseline), just after the intervention (Post6Wk) and four weeks later (Post10Wk), CMJ and knee JPS (absolute, relative and variable angular error: AAE, RAE and VAE, respectively) were evaluated.

RESULTS

ANOVA showed that the experimental group significantly decreased VAE at Post10Wk compared to baseline, suggestive of greater proprioceptive precision, while the control group significantly increased AAE, RAE and VAE at Post10Wk compared to baseline. The experimental group exhibited lower and thus, better AAE and VAE than the control group at Post10Wk, although no significant differences were found at Post6Wk. No significant differences was found in the CMJ.

CONCLUSIONS

A six weeks of multistation program may help improve proprioceptive precision of futsal players, even one month after finishing the 6-wk multistation training program. However, this is not long enough to improve proprioceptive acuity and maximum vertical jump. Therefore, the meaningful of these results in term of performance are unclear.