The Comparison of Muscle Timing between Athletes with and without Chronic Ankle Instability during Lateral Jump Landing

Research Article

Foot Ankle Stud. 2017; 1(1):1001.

The Comparison of Muscle Timing between Athletes with and without Chronic Ankle Instability during Lateral Jump Landing

Shiravi Z*, Shadmehr A, Moghadam ST and Moghadam BA

Physical Therapy Department, School of Rehabilitation, Tehran University of Medical Sciences, Iran

*Corresponding author: Shiravi Z, Physical Therapy Department, School of Rehabilitation, Tehran University of Medical Sciences, Iran

Received: November 26, 2016; Accepted: January 03, 2017; Published: January 05, 2017

Abstract

Most studies have investigated peroneal reaction time in relevant conditions of unexpected inversion perturbation occurring. The need to conduct more functional and dynamic testing that closely mimics athletic performances has been emerged.

The aim of present study was to compare premotor time and motor time of leg muscles between athletes with and without chronic ankle instability during landing phase of a lateral jump condition.

Twelve athletes with self-reported unilateral chronic ankle instability and 12 matched controls participated in the study. Participants performed lateral jump landing test during a relatively simple dynamic choice reaction task.

An electromyography device synchronized with a force plate collected data during the landing phase of lateral jump. Premotor time, motor time and reaction time of leg muscles were recorded and group differences were assessed.

Mean premotor time values for peroneus longus and tibialis anterior muscles were significantly (P=0.000, P= 0.035 respectively) greater in chronic ankle instability patients compared to controls. There was astatistically significant (p=0 .001, P= 0.014 respectively) decrease in motor time measures for peroneus longus and brevis muscles in chronic ankle instability group compared to control group. There was no statistically significant difference in reaction time between the 2 groups.

This study found muscle timing deficits in injured ankles of athletes with chronic ankle instability compared to healthy ones. The greater premotor time delay of peroneus longus and tibialis anterior muscles demonstrated in subjects with ankle instability in compared to healthy athletes should be taken in to consideration during assessment and rehabilitation programs.

Keywords: Ankle sprain; Reaction time; Premotor time; Motor time; Neuromuscular control; Choice reaction task; Force plate

Introduction

Ankle sprains are one of the most common injuries affecting athletes [1]. Many ankle injuries are found in sports that require jumping and landing such as basketball, volleyball and soccer [2]. Ankle sprains account for up to 25% of all lost time from participation in sport competitions [1]. People who experience an ankle sprain are at risk of developing Chronic Ankle Instability (CAI) which is characterized by subjective, repeated episodes of giving way after an initial ankle sprain [3]. It has been estimated that up to 80% of athletes experience a recurrent sprain [4]. Symptoms of residual instability represent in 20-40% of patients and this can lead to osteoarthritis in long term [1]. Proprioception, muscle strength, muscle reaction time, and postural control are the factors contributing to impaired neuromuscular control that is believed to be the main cause of ankle instability development [5].

Most recent studies have investigated peroneal reaction time in CAI in conditions with unexpected inversion perturbations and inconsistent results were reported [6-11]. The external validity of this type of testing is questioned since it is a controlled static position that puts the ankle in a closed-packed configuration [5]. On the other hand, there is a noticeable lack of information about muscle timing of the unstable joint in dynamic conditions such as landing movements.

The casual and dynamic nature of sports is often required for rapid and unanticipated movement responses. As a result, the need to conduct more functional and dynamic testing that most closely mimics athletic performances has been emerged.

For a given sporting task, the success of movement strategy is initially determined by an ability to react or respond to the external stimuli. This reaction time includes Pre-Motor Time (PMT) and Motor Time (MT) [12]. Reaction time can be measured by using simple dynamic Choice Reaction Task (CRT) that create conditions similar to sports.

In the past, sole use of forward jump-landing protocols probably masked the important aspects of neuromuscular control. During the lateral jump landings, the COM will oscillate primarily in the frontal plane [13]. As lateral ankle sprains occur in the frontal plane, we evaluated reaction times of leg muscles during the landing after a lateral jump.

With these facts in mind the current study aimed to Compare Premotor Time (PMT) and Motor Time (MT) of leg muscles between CAI athletes and healthy ones in landing phase of a lateral jump condition during a simple Choice Reaction Task (CRT).

Materials and Methods

Subjects

Twelve control subjects without CAI (3 females and 9 males) and 12 subjects with CAI (4 females and 8 males) voluntarily participated in the study. They were matched according to age, body mass, height, type and duration of physical activity, and lower-limb dominance. The subjects with CAI had a mean (SD) age, weight, height, and body mass index of 22.5 (3.2) years, 69.6 (11.7) kg, 1.74 (0.93) m, and 22.7 (2.4) kg/m², respectively. Additionally, individuals in the control group had a mean (SD) age, body mass, height, and body mass index of 24.0 (4.37) years, 72.7 (13.80) kg, 1.74 (0.96) m, and 23.6 (3.0) kg/m², respectively (Table 1). Participants were physical education students of Tehran University exercising regularly three times a week for at least 2 h each time. All subjects were college basketball, volleyball or football players. The side tested for those in the control group was matched to the involved side of those in the CAI group, taking in to account lower-limb dominance. Limb dominance was determined by the preferred limb used to kick a ball. In each group 10 subjects were tested on their nondominant limb and 2 subjects were tested on dominant limb.