The effects of neuro-vestibular-ocular exercises and myofascial release on proprioception and performance in football players with chronic ankle instability

Abstract

BACKGROUND AND PURPOSE:

Football players often use quick change of direction, sudden acceleration and explosive movements. This is why chronic ankle instability is one of the most common conditions affecting this athlete population. This study investigates the effects of neuro-vestibular-ocular exercises and myofascial release on proprioception and performance in football players with chronic ankle instability.

MATERIALS AND METHODS:

This randomized controlled clinical trial included 60 football players aged 18–30. The players were randomly divided into two groups. The first group (NVOEG, $n=$ 30) was included in the Neuro-Vestibular-ocular exercise training program, while the myofascial release was applied to the second group (MRHOG, $n=$ 30). Both protocols were applied for eight weeks. The participants’ Cumberland Ankle Instability Tool (CAIT) scores were assessed before and after the intervention. Proprioception was evaluated by using the joint position sense test. Additionally, kick speed (KS), 30-m sprint, zig-zag agility test (ZAT) and Landing error score system (LESS) tests were applied to evaluate their performance.

RESULTS:

Post-rehabilitation scores showed significant differences in proprioception and performance parameters compared to pre-scores in both groups. (p<0.05). Significant differences were observed between the NVOEG and MRHOG in the post-test scores, including CAIT for unstable and stable ankle, proprioception for unstable ankle, LESS, ZAT with ball performance, and 30-meter sprint test.

CONCLUSIONS:

The neuro-vulvular-ocular exercise training protocol had superior results in terms of proprioception and performance parameters in chronic ankle instability management for football players.

Keywords

Chronic ankle instability football exercise myofascial release

1. Introduction

Football is a dynamic and physically demanding sport that places significant stress on the lower extremities, particularly the ankles. As football players engage in rapid changes of direction, sudden accelerations, and explosive movements, they become susceptible to injuries, with chronic ankle instability (CAI) being one of the most prevalent conditions affecting this athlete population [1]. Football players report CAI as having the highest percentage of recurrent sprains (61%) and mechanical instability (38%) [2]. CAI refers to a condition characterized by recurring episodes of giving way, pain, and a feeling of joint instability following an initial ankle sprain [3]. These symptoms often persist beyond the acute injury phase and can impair an athlete’s performance, compromise their agility, and increase the risk of further ankle sprains [2, 4]. CAI affects an athlete’s ability to perform optimally and poses a significant risk for further injuries that can have long-term consequences on their careers [1, 5]. In the literature, several physiotherapy modalities including electrical stimulation (neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), manual therapy techniques (joint mobilizations, soft tissue mobilization, myofascial release), exercises training (balance and proprioception, neuromuscular, strengthening, plyometric, functional, sports-specific drills, agility and speed) have been reported as effective interventions for enhancing ankle stability, improve proprioception, and optimize functional performance [1, 6, 7, 8].

One of the exercise options used in CAI management is neuromuscular training (NMT). These training regimens typically encompass a repertoire of exercises, such as strengthening, stretching routines, plyometric activities, and balance exercises, to maximize sensory control and compensatory functional stability [9, 10]. In the study conducted by Kim et al. [11], sixty-seven athletes diagnosed with CAI were randomly divided into three groups: a neuromuscular training group (NG), a strength training group (SG), and a control group (CG). Over eight weeks, significant differences were observed between the SG and the CG regarding the posteromedial direction for balance and Foot and Ankle Ability Measure (FAAM-SPORT) scores for the functionality of the lower extremities [12]. Cruz-Diaz et al. [13] conducted a study involving 70 athletes diagnosed with CAI. The control group continued with their usual strength-training workout routine. In contrast, the intervention group performed the same usual training routine for six weeks, along with a balanced program. The study found that this intervention significantly improved dynamic balance and Cumberland Ankle Instability Tool (CAIT) scores.

Vestibular exercise training aims to alleviate dizziness and imbalance caused by peripheral vestibular dysfunction, and it focuses on stimulating the central nervous system to compensate for the dysfunction in the vestibular system. Suppose sensory and balance information is not accurate. In that case, an athlete may experience delayed reaction time and may not be able to maintain symptoms such as dizziness, disorientation or a feeling of instability, recovering after a change of direction [14]. In order to maintain balance and visual stability during dynamic activities, this reflex, which synchronizes eye movements with head movements, is crucial [15]. Although there are studies examining the effects of different exercises on vestibular/ocular motor assessment in recreational athletes, there is no study in the literature showing that investigating the effectiveness of vestibular/ocular exercises on football players [16, 17]. A study assessed the VOR function in athletes participating in ball sports. The researchers measured the reaction time of postrotary nystagmus (PRN) induced by a swivel chair. Both groups underwent vestibular stimulation through passive head rotation in clockwise and counterclockwise directions, with a 30-minute interval between rotations. The researchers concluded that the faster recovery time of PRN in ball sports athletes may be attributed to rapid signal processing in the central nervous system [18].

Clinicians frequently employ manual therapy techniques to address musculoskeletal limitations and restrictions, aiming to alleviate pain and restore mobility. The presence of adhesions within the fascia can impede joint range of motion (ROM) and restrict the flexibility of soft tissues such as muscles, ligaments, and tendons, consequently diminishing the capacity for muscle power generation. Suppose an athlete’s fascia is well-trained to provide optimum elasticity and flexibility. In that case, their performance can be enhanced effectively and at the same time, they can greatly protect themselves from injury [19]. A randomized controlled trial involving 36 football players with recurrent ankle sprains was divided into groups. The experimental groups received myofascial release (MFR) and neuromuscular exercise with banding. The control group received the same interventions without neuromuscular banding. The findings indicated that combining fascial therapy and eccentric strength training with banding improved ankle mobility, strength, and stability [20]. In another study examining the effects of combining manual therapy with Foam Roller (FR) and myofascial relaxation versus FR alone, researchers focused on varsity athletes participating in basketball, field football, and volleyball. The study found that MFR using FR resulted in more significant improvements in ROM, muscle strength related to jump height, and strength related to Repetition Maximum (RM) compared to FR alone [21].

The study of the influence of neuro-vestibular-ocular exercises and myofascial release on proprioception and bringing results in football players with Chronic Ankle Instability (CAI) is essential for several reasons. Firstly, CAI is a relatively common problem among footballers, having the consequences of recurrent ankle sprains and reduced playing levels. Discovering the efficacy of rehabilitation protocols in CAI management is one of the most vital elements of enhancing players’ health and productivity [22]. Proprioception is another subtle skill used in sports, especially in activities involving much movement, such as football. The study of the effect of different rehabilitation treatments on proprioception to make players more stable and prevent any further injuries can bring up critical information in that regard. An additional emerging rehabilitation method that has shown potential in enhancing proprioception and functional outcomes is neuro-vestibular-ocular exercises and myofascial release among different populations. Examining the responses of football players with CAI to such changes can further customize their rehabilitation programs to closely resemble the physical demands of the sport and the condition, thus paving the way towards more efficient treatments [23]. In conclusion, research on the influence of neuro-vestibular-ocular exercises and myofascial release procedures on proprioception and performance in football players experiencing CAI is seen as a fundamental factor in progressing knowledge on optimum treatment methods for this group of athletes. This type of research would eventually lead to the promotion of healthier players, reduction of injury rates, and improvement of the players’ performance. According to the literature, although there are studies investigating the effectiveness of neuromuscular exercises for football players with CAI, there is no study of neuromuscular exercises with vestibular ocular exercises. In addition, the number of studies examining the effectiveness of manual therapy applications for athletes is still insufficient [22, 24]. As far as we know, no study has investigated the effectiveness of both myofascial releasing and neuromuscular-vestibular-ocular exercise training protocols or examined the superiority of training programs. Therefore, the aim of this study is to investigate the effects of two different rehabilitation protocols, neuro-vestibular-ocular exercises and myofascial release, on proprioception and performance in football players with CAI.

2. Methods

2.1 Study design

A prospective, single-blinded, randomized, controlled trial was performed at the two different sports clubs. These sports clubs were training with the same coach. Before the study, informed consent was obtained from all participants, who were informed about the evaluation and treatment protocol. This study was approved by the decision of the University Ethics Committee by the Declaration of Helsinki (protocol number: 200). This study was registered on ClinicalTrials.gov with the registration number NCT05799885. The players who volunteered to participate in the study were selected by considering the following inclusion and exclusion criteria. The sample size of the randomized controlled study was calculated with the G * Power 3.1.9.7 program. In power analysis, the effect size was 0.76; the Type I error was 0.05; the allocation ratio was 1 (alpha, 0.05, and power, 0.80), and the number of cases to be included for both groups was 30 [15]. The participants were randomly assigned to one of two parallel groups to receive a Neuro-Vestibular-ocular exercise group (NVOEG) and a myofascial release “hands-on” group (MRHOG) using an online research randomizer computer-based generator [25].

2.2 Participants

The study included 63 male football players who were divided into two groups: NVOEG ( $n=$ 30, 25 years) and MRHOG ( $n=$ 30, 24 years) (Fig. 1). The study excluded three participants since they did not meet the inclusion criteria. Inclusion criteria were determined to be 18–30 years, having at least two previous lateral sprains in the same ankle, having had at least one “giving way” episode in the previous six months, and no other lower extremity injuries. Players with a score of $\leqslant$ 27 on the Cumberland ankle instability scale (CAIT) were also included in the study. Participants’ left and right ankles were tested using the CAIT [15]. The players who had bilateral ankle instability, a history of musculoskeletal surgery and fractures in the lower extremities, a history of acute injury to the musculoskeletal structures of other lower extremity joints in the last three months, affecting joint integrity and function and causing interruption of the desired physical activity for at least one day and having a history of balance and vestibular disorders were excluded from the study. The demographic and clinical baseline variables of the participants are presented in Table 1. At baseline, no significant differences were observed between groups for demographic and clinical variables ( $p>$ 0.05).

Table 1
Baseline features of groups

	Group		Test statics
	NVOEG	MRHOG	$t$	$p$
	( $n=$ 30)	( $n=$ 30)
Age, (year)
Mean $\pm$ SD	24.47 $\pm$ 2.33	24.33 $\pm$ 2.60	0.21^†	0.83
$M$ (min-max)	25 (20–28)	25 (19–28)
Height, (cm)
Mean $\pm$ SD	177.97 $\pm$ 4.55	181.63 $\pm$ 2.62	$-$ 0.82^†	0.11
$M$ (min-max)	177 (166–188)	182 (175–186)
Weight, (kg)
Mean $\pm$ SD	71.93 $\pm$ 4.25	76.60 $\pm$ 2.65	$-$ 1.11^†	0.10
$M$ (min-max)	71.50 (62–80)	76.50 (71–82)
BMI, (kg/m²)
Mean $\pm$ SD	22.69 $\pm$ 0.41	23.20 $\pm$ 0.26	0.73^†	0.09
$M$ (min-max)	22.55 (22–23.40)	23.20 (22.60–23.70)
Playing time, (year)
Mean $\pm$ SD	10.70 $\pm$ 0.84	10.27 $\pm$ 0.91	1.92^†	0.05
$M$ (min-max)	10 (10–12)	10 (9–12)
Dominant side, $n$ (%)
Right	25 (83.3%)	27 (90%)	0.71^‡	0.35
Left	5 (16.7%)	3 (10%)
Unstable ankle, $n$ (%)
Right	16 (53.3%)	18 (60%)	0.80^‡	0.39
Left	14 (46.7%)	12 (40%)

NVOEG: Neuro-vestibulo-occular exercise group, MRHOG: myofacial release “hands-on” group. ^†Independent Samples $t$ -test (t); ^‡Chi-Square Test ( $\chi^{2}$ ); Data expressed as mean $\pm$ standard deviation and Median (minimum, maximum) for numerical data and categorical data shown as percentage (%).

Figure 1.

CONSORT (Consolidated Standards of Reporting Trials) flow chart of participant.

2.3 Assessment procedures

A pre-structured questionnaire was filled out through face-to-face interviews to get their physical and clinical features (age, body mass index, presence of chronic diseases, hand dominance, training habits, surgical conditions, and players’ position). All players’ ankle proprioception (inversion and eversion) was evaluated using the joint position sense test (JPST). Some performance parameters, including kick speed (KS), agility and jump landing, were also assessed. All measurements were performed at baseline and after an eight-week intervention by the same blinded physiotherapist. Also, all measurements were made using the same artificial turf and indoor gym environment.

The ankle proprioception was measured with the JPST, which measured the deviations from the targeted angle using a goniometer. Firstly, the participants were asked to close their eyes, the goniometer was set to zero, and the ankle subtalar joint was placed in the neutral position. The ankle was passively inverted 20 degrees, everted 10 degrees, and maintained for 5 seconds. The person was asked to remember this position. Then, the foot was guided to a neutral or starting position. The subjects were then instructed to reposition the foot to the target angle. After three different measurements, the deviations of the participants from the target angle were measured and recorded [24].

KS, 30-m sprint, zig-zag test (ZAT) and Landing error score system (LESS) were also applied to evaluate their performance. LESS is used to evaluate performance, which is called jump landing biomechanics. For the jump landing assessment, a 30-cm high box with a non-slippery surface was prepared, and each participant was asked to jump the distance at least half their height. The researchers gave the jumping process to the participants one by one, and the participants allowed three jump attempts. Cameras were fixed to the front of the jump area and the side of the leg under test (camera-enabled smartphones), and video recordings were taken during the jumps. The distance of the cameras from the jump area is 345 cm, and the distance of the camera lens from the ground is 122 cm. No commands were given during the application; the participants were expected to make a free landing on the ground with a jump and a vertical jump immediately after. According to the jump protocol, each player repeated the jump landing three times. A free video-based image analysis program examined the jump images captured during the jump testing [26]. The agility of participants was evaluated by using a 30-meter Sprint and ZAT. For the 30-meter Sprint Test, players performed maximum-effort 30-meter sprints three times on the field. Between each sprint, a rest period of 3 minutes was given. The shortest time was recorded, which covered the 30-meter distance during the sprint test. Before each sprint test, players participated in a 10-minute running session at 60–70% of their maximum heart rate, followed by 5 minutes of exercises that included short jumps of 5 to 10 meters, walking and a 2-minute rest period. Timings were recorded with a stopwatch and a video recording system with phone support. The ZAT was performed with and without the ball to assess participants’ agility. Players underwent the zig-zag agility test on a synthetic turf field three times, with a two-minute rest interval between each trial. The time measured using a stopwatch for the shortest performance in the zig-zag agility tests, both with and without the ball, was recorded. Soccer kicking speed performance was evaluated based on the shot’s ball speed. Cones were positioned one and two meters from the ball’s starting position. According to Federation Internationale de Football Association (FIFA) regulations, a ball of standard size and sufficient pressure were utilized for this measurement. Each participant ran three trials with instable side (affected) and the times from these trials were averaged. Between each trial, there was a 20-second rest time. Each participant engaged in three trials using each leg. The measurements were made using the video analysis method in the “speed gun” application [27, 28].

2.4 Interventions

The participants recruited in the neuro-vestibular-ocular exercise group (NVOEG), and myofascial release “hands-on” group (MRHOG) received different interventions twice a week for eight weeks. The NVOEG received a Neuro-Vestibular-ocular exercise training protocol, and the MRHOG received a MFR technique (Fig. 1). All subjects received the initial participant education and strength exercises program instruction. A physiotherapist applied the Neuro-Vestibular-ocular exercise training protocol for an hour twice weekly. Participants in NVOEG tried to maintain their balance with eye and head movements with hop stabilization exercises to provide neuromuscular control, strength, and static and dynamic balance on different surfaces [15]. The details of the training protocol for NVOEG are shown in Table 2. This protocol consists of 4 phases involving progression.

Table 2
Training protocol for neuro-vestibular-ocular group

Neuro-vestibular-ocular training	Phase 1 (Week 1–2)	Phase 2 (Week 3–4)	Phase 3 (Week 5–6)	Phase 4 (Week 7–8)
Jumping and Stabilization Focus	Arms in cross position on the chest, 30 seconds on Thera-Band Stability Trainer, Hopping 45.7-cm while hands on the hips	Arms in cross position on the chest, 60 seconds on Thera-Band Stability Trainer, Hopping 68.6-cm while hands on the hips	Arms in cross position on the chest, 60 seconds on BOSU ball, Hopping 91.4-cm while hands on the hips	Arms in cross position on the chest, 60 seconds on Balance Disc, Hopping 91.4-cm while hands free
Sport Specific and Unanticipated Hop to Stabilization Focus	One Leg Jumps and Each move has a time limit of 5 seconds	One Leg Jumps and Each move has a time limit of 3 seconds	One Leg Squat Jumps and Each move has a time limit of 3 seconds	One Leg Squat Jumps and Each move has a time limit of 1 seconds
Strength Focus	4 way ankle theraband Exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Double leg heel raises: (3 sets $\times$ 12 reps)	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Double leg heel raises: (3 sets $\times$ 12r eps)	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Squat (2 sets $\times$ 10 reps) Lunge (2 sets $\times$ 10 reps) Plank (2 sets $\times$ 10 reps)	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Single leg heel raises: (3 sets $\times$ 12 reps) Squat (2 sets $\times$ 10 reps) Lunge (2 sets $\times$ 10 reps) Plank (2 sets $\times$ 10 reps)

Table 3

Training protocol for myofascial release hands-on group

Myofascial release hands-on training	Phase 1 (Week 1–2)	Phase 2 (Week 3–4)	Phase 3 (Week 5–6)	Phase 4 (Week 7–8)
	Plantar Facia MFR Gastrocnemius MFR Soleus MFR Hamstring MFR 2 Repetitions	Plantar Facia MFR Gastrocnemius MFR Soleus MFR Hamstring MFR 3 Repetitions	Plantar Facia MFR Gastrocnemius MFR Soleus MFR Hamstring MFR 4 Repetitions	Plantar Facia MFR Gastrocnemius MFR Soleus MFR Hamstring MFR 5 Repetitions
Strength Focus	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Double leg heel raises: (3 sets $\times$ 12 reps)	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Double leg heel raises: (3 sets $\times$ 12 reps)	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Squat (2 sets $\times$ 10 reps) Lunge (2 sets $\times$ 10 reps) Plank (2 sets $\times$ 10 reps)	4 way ankle theraband exercises (3 sets $\times$ 12 reps) Foot intrinsic strengthening (toe curl, doming) Single leg heel raises: (3 sets $\times$ 12 reps) Squat (2 sets $\times$ 10 reps) Lunge (2 sets $\times$ 10 reps) Plank (2 sets $\times$ 10 reps)

The same physiotherapist applied MFR techniques to the plantar fascia, gastro-soleus, and hamstring muscles for eight weeks after the assessments. For MRHOG, the MFR sessions lasted approximately one hour. The treatment protocol consisted of four different phases according to progression (Table 3).

Table 4

Comparison of pre-test scores between groups

	Group		Test statistics^†
	NVOEG	MRHOG	$t$	$p$
	( $n=$ 30) Mean $\pm$ SD	( $n=$ 30) Mean $\pm$ SD
LESS Test	6.94 $\pm$ 0.53	6.90 $\pm$ 0.55	0.185	0.85
CAIT unstable	24.00 $\pm$ 0.87	24.37 $\pm$ 1.00	$-$ 1.52	0.13
CAIT stable	29.07 $\pm$ 0.67	29.23 $\pm$ 0.68	$-$ 0.94	0.35
Kicking speed unstable	19.56 $\pm$ 2.68	19.85 $\pm$ 2.47	$-$ 0.44	0.66
Kicking speed stable	24.87 $\pm$ 2.96	24.78 $\pm$ 2.52	0.12	0.90
Zigzag without ball	8.18 $\pm$ 0.84	8.25 $\pm$ 0.38	$-$ 0.40	0.69
Zigzag with ball	10.55 $\pm$ 1.02	10.59 $\pm$ 0.92	$-$ 0.15	0.88
Number of ankle sprain	5.20 $\pm$ 0.55	4.93 $\pm$ 0.52	1.93	0.05
Proprioception (inversion UA)	4.53 $\pm$ 0.68	4.57 $\pm$ 0.68	$-$ 0.19	0.85
Proprioception (inversion SA)	2.67 $\pm$ 0.74	2.53 $\pm$ 0.73	$-$ 1.41	0.16
Proprioception (eversion UA)	3.63 $\pm$ 0.72	3.70 $\pm$ 0.75	$-$ 0.35	0.70
Proprioception (eversion SA)	1.83 $\pm$ 0.70	1.50 $\pm$ 0.73	1.81	0.07
30 m sprint test	6.75 $\pm$ 0.57	6.57 $\pm$ 0.51	1.27	0.21

NVOEG: Neuro-vestibular-ocular exercise group, MRHOG: Myofascial release “hands-on” group. LESS: Landing error score system, CAIT: Cumberland Ankle Instability Tool, SA: Stable ankle, UA: Unstable ankle. ^†Independent Samples $t$ -test; Descriptive statistics were given as mean $\pm$ standard deviation. Significance level was set at $p<$ 0.05.

2.5 Statistical analysis

The Statistical Package for the Social Sciences 26.0 (SPSS) program was used for all statistical analyses. A Kolmogorov–Smirnov test was used to assess the data distribution. The data were normally distributed; thus, a parametric test was used for statistical analysis. Demographic and clinical baseline variables were compared between the groups using an independent sample $t$ -test for continuous variables and a chi-square test for categorical data. The significance level was set at $p<$ 0.05.

Table 5
Comparison of post-test results between groups

	Group		Test statistics^†
	NVOEG	MRHOG	$t$	$p$
	( $n=$ 30) Mean $\pm$ SD	( $n=$ 30) Mean $\pm$ SD
LESS Test	4.53 $\pm$ 0.35	5.20 $\pm$ 0.42	$-$ 6.80	0.00
CAIT unstable	26.33 $\pm$ 0.66	25.73 $\pm$ 0.83	3.10	0.00
CAIT stable	29.83 $\pm$ 0.38	29.40 $\pm$ 0.56	3.50	0.00
Kicking speed unstable	24.23 $\pm$ 3.00	23.60 $\pm$ 2.41	0.90	0.30
Kicking speed stable	27.72 $\pm$ 3.04	26.68 $\pm$ 2.64	1.44	0.15
Zigzag without ball	5.80 $\pm$ 0.60	5.85 $\pm$ 0.27	$-$ 0.50	0.62
Zigzag with ball	6.85 $\pm$ 0.59	7.30 $\pm$ 0.64	$-$ 2.89	0.00
Proprioception (inversion UA)	2.57 $\pm$ 0.50	3.47 $\pm$ 0.68	$-$ 5.86	0.00
Proprioception (inversion SA)	1.83 $\pm$ 0.38	1.93 $\pm$ 0.60	$-$ 0.77	0.44
Proprioception (eversion UA)	2.13 $\pm$ 0.35	2.90 $\pm$ 0.66	$-$ 5.62	0.00
Proprioception (eversion SA)	1.27 $\pm$ 0.28	1.23 $\pm$ 0.34	0.41	0.68
30 m sprint test	4.48 $\pm$ 0.28	5.28 $\pm$ 0.28	$-$ 11.15	0.00

Table 6

Comparison of pre-test and post-test results intra-groups

	NVOEG			MRHOG
	( $n=$ 30)			( $n=$ 30)
	Mean $\pm$ SD	$t$ ^ϕ	$p$ ^ϕ	Mean $\pm$ SD	$t$ ^&	$p$ ^&
LESS test
Pre-test	6.94 $\pm$ 0.53	71.14	0.00	6.90 $\pm$ 0.55	68.56	0.00
Post-test	4.53 $\pm$ 0.35			5.20 $\pm$ 0.42
CAIT unstable
Pre-test	24.00 $\pm$ 0.87	$-$ 21.07	0.00	24.37 $\pm$ 1.00	$-$ 15.27	0.00
Post-test	26.33 $\pm$ 0.66			25.73 $\pm$ 0.83
CAIT stable
Pre-test	29.07 $\pm$ 0.67	$-$ 8.33	0.00	29.23 $\pm$ 0.68	$-$ 2.41	0.02
Post-test	29.83 $\pm$ 0.38			29.40 $\pm$ 0.56
Kicking speed unstable
Pre-test	19.56 $\pm$ 2.68	$-$ 19.33	0.00	19.85 $\pm$ 2.47	$-$ 16.18	0.00
Post-test	24.23 $\pm$ 3.00			23.60 $\pm$ 2.41
Kicking speed stable
Pre-test	24.87 $\pm$ 2.96	$-$ 65.04	0.00	24.78 $\pm$ 2.52	$-$ 33.62	0.00
Post-test	27.72 $\pm$ 3.04			26.68 $\pm$ 2.64
Zigzag without ball
Pre-test	8.18 $\pm$ 0.84	32.18	0.00	8.25 $\pm$ 0.38	117.82	0.00
Post-test	5.80 $\pm$ 0.60			5.85 $\pm$ 0.27
Zigzag with ball
Pre-test	10.55 $\pm$ 1.02	46.71	0.00	10.59 $\pm$ 0.92	62.81	0.00
Post-test	6.85 $\pm$ 0.59			7.30 $\pm$ 0.64
Proprioception (inversion UA)
Pre-test	4.53 $\pm$ 0.68	26.03	0.00	4.57 $\pm$ 0.68	19.75	0.00
Post-test	2.57 $\pm$ 0.50			3.47 $\pm$ 0.68
Proprioception (inversion SA)
Pre-test	2.67 $\pm$ 0.74	4.71	0.00	2.53 $\pm$ 0.73	9.20	0.00
Post-test	1.83 $\pm$ 0.38			1.93 $\pm$ 0.60
Proprioception (eversion UA)
Pre-test	3.63 $\pm$ 0.72	16.16	0.00	3.70 $\pm$ 0.75	10.77	0.00
Post-test	2.13 $\pm$ 0.35			2.90 $\pm$ 0.66
Proprioception (eversion SA)
Pre-test	1.83 $\pm$ 0.70	6.30	0.00	1.50 $\pm$ 0.73	3.12	0.00
Post-test	1.27 $\pm$ 0.28			1.23 $\pm$ 0.34
30 m sprint test
Pre-test	6.75 $\pm$ 0.57	38.32	0.00	6.57 $\pm$ 0.51	19.85	0.00
Post-test	4.48 $\pm$ 0.28			5.28 $\pm$ 0.28

NVOEG: Neuro-vestibular-ocular exercise group, MRHOG: Myofascial release “hands-on” group. LESS: Landing error score system, CAIT: Cumberland Ankle Instability Tool, SA: Stable ankle, UA: Unstable ankle. ^ϕPaired Samples t-test statistics for NVOEG, ^&Paired Samples $t$ -test statistics for MRHOG. Descriptive statistics were given as mean $\pm$ standard deviation. Significance level was set at $p<$ 0.05.

3. Results

A total of 30 football players with CAI were randomized to the Neuro-Vestibular-Ocular exercise group (NVOEG) and 30 to the MFR hands-on group (MRHOG); please see the CONSORT flow chart (Fig. 1). According to Table 1, a total of 60 patients, 30 of whom were in the NVOEG and the MRHOG groups, were included in the study. The median age of the patients was 25 for both the NVOEG and MRHOG groups. The differences between the ages of the patients in the groups were not statistically significant ( $p>$ 0.05). The BMI for the NVOEG group was 22.69 $\pm$ 0.41, and the MRHOG group was 23.20 $\pm$ 0.26. The groups had no significant difference according to BMI ( $p>$ 0.05). The median playing time of the patients was ten years for both groups. The differences between the playing times of the patients in the groups were not statistically significant ( $p>$ 0.05). The dominant side for 83.3% of the patients in the NVOEG group was right, while 90% was in the MRHOG group. There was no significant difference between the groups regarding the dominant side ( $p>$ 0.05). On the other hand, the unstable ankle for 53.3% of patients in the NVOEG group was right, while 60% in the MRHOG group. There was no significant difference between the groups regarding unstable knees ( $p>$ 0.05).

At baseline, no statistically significant differences were observed in the pre-test scores of all variables between groups ( $p>$ 0.05, Table 4).

A comparison of post-test scores between the groups is shown in Table 5. LESS Test results, CAIT score for unstable ankle, CAIT score for stable ankle, ZAT with ball, proprioception variables of inversion and eversion for unstable ankle and 30-m sprint test results significantly different between NVOEG and MRHOG groups ( $p<$ 0.05, Table 5).

As seen in Table 6, CAIT scores for both unstable and stable ankles and KS scores for both unstable and stable sides significantly increased for both NVOEG and MRHOG groups after the eight-week intervention period ( $p<$ 0.05). On the other hand, the results of the LESS, ZAT with and without the ball, proprioception of inversion and eversion for unstable and stable ankles, and 30-m sprint test significantly decreased for both groups after intervention ( $p<$ 0.05, Table 6).

According to Table 7, significant differences were found for fewer results in CAIT scores for unstable and stable ankles, KS for unstable and stable ankles, ZAT without the ball, proprioception of inversion for unstable ankles, proprioception of eversion for unstable and stable ankles, and 30-m sprint test between NVOEG and MRHOG groups ( $p<$ 0.05, Table 7).

Table 7
Comparison of differences for pre and post-tests between groups

	Group		Test statistics^†
	NVOEG	MRHOG	$t$	$p$
	( $n=$ 30) Mean $\pm$ SD	( $n=$ 30) Mean $\pm$ SD
LESS test	$-$ 2.41 $\pm$ 0.19	$-$ 1.71 $\pm$ 0.14	$-$ 16.67	0.00
CAIT unstable	2.33 $\pm$ 0.61	1.37 $\pm$ 0.49	6.79	0.00
CAIT stable	0.77 $\pm$ 0.50	0.17 $\pm$ 0.38	5.21	0.00
Kicking speed unstable	4.67 $\pm$ 1.32	3.75 $\pm$ 1.27	2.77	0.00
Kicking speed stable	2.85 $\pm$ 0.24	1.90 $\pm$ 0.31	13.39	0.00
Zigzag without ball	$-$ 2.39 $\pm$ 0.41	$-$ 2.39 $\pm$ 0.11	0.09	0.92
Zigzag with ball	$-$ 3.70 $\pm$ 0.43	$-$ 3.28 $\pm$ 0.29	$-$ 4.44	0.00
Proprioception (inversion UA)	$-$ 1.77 $\pm$ 0.91	$-$ 1.10 $\pm$ 0.31	9.23	0.00
Proprioception (inversion SA)	$-$ 0.43 $\pm$ 0.50	$-$ 0.60 $\pm$ 0.36	1.48	0.14
Proprioception (eversion UA)	$-$ 1.50 $\pm$ 0.51	$-$ 0.48 $\pm$ 0.41	$-$ 5.89	0.00
Proprioception (eversion SA)	$-$ 0.57 $\pm$ 0.49	$-$ 0.27 $\pm$ 0.47	$-$ 2.42	0.01
30-m sprint test	$-$ 2.27 $\pm$ 0.32	$-$ 1.29 $\pm$ 0.36	$-$ 11.17	0.00

NVOEG: Neuro-vestibular-ocular exercise group, MRHOG: Myofascial release ‘hands-on” group. LESS: Landing error score system, CAIT: Cumberland Ankle Instability Tool, SA: Stable ankle, UA: Unstable ankle. ^†Independent Samples $t$ -test; Descriptive statistics were given as mean $\pm$ standard deviation. Significance level was set at $p<$ 0.05.

4. Discussion

Chronic ankle instability (CAI) is a common condition among football players that can significantly impact their performance and overall proprioception [1]. The study results revealed significant improvements in proprioception and performance in both groups. However, the neuro-vestibular-ocular exercise group exhibited superior outcomes to the myofascial release group. These findings emphasize the importance of incorporating neuro-vestibular-ocular exercises and myofascial release into the treatment regimen for CAI in football players.

Integrating multiple sensory inputs becomes essential in sports like football, basketball, and volleyball, where quick and precise movements are crucial. However, CAI can disrupt this integration, leading to compromised proprioception and reduced leg stability, which are detrimental to football performance. Therefore, rehabilitation protocols CAI become essential to optimize these skill parameters and enhance overall football performance [2]. In the study involving elite football players ( $n=$ 20), researchers investigated the impact of a 6-week NMT program on agility performance. The participants were randomly divided into two groups: an NMT group ( $n=$ 10), which engaged in exercises such as plyometrics and dynamic stability, and an active control group ( $n=$ 10). The participants in the NMT group engaged in dynamic stability, balance, and core strength exercises in the gym. At the same time, on-field activities included agility drills, cutting manoeuvres, and plyometric exercises. The study demonstrated that this 6-week NMT program significantly improved return performance (180^∘) and agility performance among elite football players [29]. In the current study, for the ZAT with a ball, the post-intervention scores for the NVOEG group were significantly lower than those for the MRHOG group ( $p<$ 0.05), indicating that the former group performed the task more quickly. All proprioception parameters improved after intervention in both groups ( $p<$ 0.05, Table 6). Neuro-vestibular-ocular training may have been more effective on the agility performance of the players (except for the ZAT without the ball) between groups ( $p<$ 0.05, Table 7). This protocol’s superiority can be attributed to the multifaceted sensorimotor training involved in the neuro-vestibular-ocular exercises, which might have improved motor coordination and balance, both vital for agility when handling a ball.

Manual therapy techniques, specifically myofascial release, can be an effective component of the rehabilitation protocol for football players with CAI. The impact of applying fascial tissue equipment to the lower extremities’ posterior group muscles on athletic performance varies in the literature. However, manual techniques, stretching exercises, and other forms of exercise have positively affected performance in a few studies [21, 22, 30]. In research conducted with 20 football players participating in the Amateur League, the application of self-myofascial relaxation using a foam roller was investigated. The results indicated that the foam roller application did not change the athletes’ anaerobic power performance. However, it enhanced the players’ balance and functional movement scores [30]. In a comparative study involving 30 amateur football players, the effects of MFR and passive stretching on hamstring flexibility were examined. The first group received myofascial release; the second group underwent passive stretching. The results indicated that myofascial relaxation and passive stretching effectively enhanced hamstring flexibility. When comparing the two groups, myofascial relaxation was more effective than passive stretching in improving hamstring flexibility [31]. Another study investigated the effectiveness of combining MFR with Proprioceptive Neuromuscular Facilitation (PNF) stretching on hamstring tension in football players. The group that underwent MFR combined with PNF stretching demonstrated significantly more improvement in the sit-and-reach test scores [32]. In our study results, post-test measurements demonstrated a significant reduction in sprint times, all ZAT with and without the ball and LESS results, proprioception values of unstable and stable ankles for both groups ( $p<$ 0.05, Tables 6 and 7). The current study results support that the neuro-vestibular-ocular protocol is more beneficial for proprioception and performance parameters than the MFR technique.

In the existing literature, some studies have been available that assess the effectiveness of neuromuscular exercise programs in football players with CAI [10]. However, there are limitations, variability and controversy regarding the methods used for myofascial release, which adds complexity to the understanding of this topic. Additionally, due to the lack of research on the neuro-vestibular-ocular reflex training protocols in CAI, we found it difficult to compare the findings of our study with those of others. Therefore, we compared it with NMT and the limited number of vestibular-ocular training. Although this study had a few limitations, the desired sample size was achieved according to the power analysis result. However, it is crucial to continue expanding this research to more extensive and more diverse athletic populations and to determine the long-term effects of vestibular-ocular reflex training on balance, proprioception, and strength in CAI.

5. Conclusion

This study provides comprehensive evidence supporting the efficacy of neuro-vestibular-ocular exercises and myofascial release therapy in improving proprioception and performance parameters in football players with CAI. The value of neuro-vestibular-ocular exercises, as evidenced in this study, could herald a new standard in sports rehabilitation, augmenting traditional physiotherapy approaches such as myofascial release therapy. Furthermore, these findings may prompt football coaches and trainers to incorporate neuro-vestibular-ocular exercises into routine training to potentially mitigate the risk of ankle instability and enhance proprioception and performance. This could lead to a healthier, more resilient team and a lower risk of injuries often accompanying this highly competitive sport.

Author contributions

CONCEPTION: ETÇ.

PERFORMANCE OF WORK: BK.

INTERPRETATION OR ANALYSIS OF DATA: ETÇ & BK.

PREPARATION OF THE MANUSCRIPT: ETÇ & BK.

REVISION FOR IMPORTANT INTELLECTUAL CONTENT: ETÇ & BK.

SUPERVISION: ETÇ.

Ethical approval

Participants provided written informed consent, which had been approved by the ethical committee at the Faculty of Health Sciences of Yeditepe University. (IRB study protocol:200).

Funding

The authors report no funding.

Clinical trial registry name and registration number

YEDITEPEU-BUSRAKOCAKILIC-0096/NCT0579 9885.

Footnotes

Conflict of interest

The authors have no conflicts of interest to report.

References

Walls

Ross

Fraser

, et al. Football injuries of the ankle: A review of injury mechanisms, diagnosis and management. World J Orthop. 2016; 7(1): 8.

Attenborough

Hiller

Smith

Stuelcken

Greene

Sinclair

. Chronic ankle instability in sporting populations. Sports Med. 2014; 44: 1545-1556.

Herzog

Kerr

Marshall

Wikstrom

. Epidemiology of ankle sprains and chronic ankle instability. J Athl Train. 2019; 54(6): 603-610.

Hertel

Corbett

. An updated model of chronic ankle instability. J Athl Train. 2019; 54(6): 572-588.

Hantal

Şaylı

Subaşı

, et al., Chronic ankle instability and associated factors in the general population: a pilot study. Adv Rehab. 2022; 36(1).

Coelho-Oliveira

Taiar

Pessanha-Freitas

, et al. Effects of Whole-Body Vibration Exercise on Athletes with Ankle Instability: A Systematic Review. Int. J. Environ. Res. Public Health. 2023; 20(5): 4522.

Mattacola

Dwyer

. Rehabilitation of the ankle after acute sprain or chronic instability. J Athl Train. 2002; 37(4): 413.

Postle

Pak

Smith

. Effectiveness of proprioceptive exercises for ankle ligament injury in adults: a systematic literature and meta-analysis. Man. Ther. 2012; 17(4): 285-291.

O’Driscoll

Delahunt

. Neuromuscular training to enhance sensorimotor and functional deficits in subjects with chronic ankle instability: a systematic review and best evidence synthesis. Sports Med Arthrosc Rehabil Ther Technol. 2011; 3(1): 1-20.

10.

Hall

Chomistek

Kingma

Docherty

. Balance-and strength-training protocols to improve chronic ankle instability deficits, part I: Assessing clinical outcome measures. J Athl Train. 2018; 53(6): 568-577.

11.

Kim

Estepa-Gallego

Estudillo-Martínez

Castellote-Caballero

Cruz-Díaz

. Comparative effects of neuromuscular-and strength-training protocols on pathomechanical, sensory-perceptual, and motor-behavioral impairments in patients with chronic ankle instability: randomized controlled trial. Healthcare. 2022; 10(8): 1364.

12.

Cloak

Nevill

Day

Wyon

. Six-week combined vibration and wobble board training on balance and stability in footballers with functional ankle instability. Clin J Sport Med. 2013; 23(5): 384-391.

13.

Cruz-Diaz

Lomas-Vega

Osuna-Pérez

Contreras

Martínez-Amat

. Effects of 6 weeks of balance training on chronic ankle instability in athletes: a randomized controlled trial. Int. J. Sports Med. 2015; 754-760.

14.

Han

. Vestibular Rehabilitation Therapy: Review of Indications, Mechanisms, and Key Exercises. Simplified Vestibular Rehabilitation Therapy; 2021.

15.

Cerbezer

Çil

Subaşı

. The effect of neuromuscular and vestibular-ocular reflex training program on balance, isokinetic muscle strength and proprioception in people with chronic ankle instability. The Foot. 2023; 56: 101992.

16.

Khanal

. Impact of visual skills training on sports performance: current and future perspectives. Adv Ophthalmol Vis Syst. 2015; 2(1): 26-28.

17.

White-Schwoch

Krizman

McCracken

, et al. Performance on auditory, vestibular, and visual tests is stable across two seasons of youth tackle football. Brain Inj. 2020; 34(2): 236-244.

18.

Hsieh

Chang

Chen

. Assessment of Vestibulo-Ocular Reflex Function in Ball Sports Athletes. 2019; 21(4): 353-362.

19.

Schleip

Müller

. Training principles for fascial connective tissues: scientific foundation and suggested practical applications. J Bodyw Mov Ther. 2013; 17(1): 103-115.

20.

Allois

Niglia

Pernice

Cuesta-Barriuso

. Fascial therapy, strength exercises and taping in soccer players with recurrent ankle sprains: A randomized controlled trial. J Bodyw Mov Ther. 2021; 27: 256-264.

21.

Afanador-Restrepo

Rodríguez-López

Rivas-Campo

, et al. Effects of Myofascial Release Using Finding-Oriented Manual Therapy Combined with Foam Roller on Physical Performance in University Athletes. A Randomized Controlled Study. Int. J. Environ. Res. Public Health. 2023; 20(2): 1364.

22.

Jeong

Kim

. Effects of whole body vibration exercise on lower extremity muscle activity and balance ability in football player with chronic ankle instability. J Korean Phys Ther. 2017; 29(6): 293-298.

23.

Subramanian

Teng

Senthil

Gaowgeh

Alfawaz

Neamatallah

. Correlation between Level of Functional Ability and Sports Performance among Football Players with Chronic Ankle Instability (CAI). J Pharm Res Int. 2021; 33: 415-24.

24.

Melam

Alhusaini

Perumal

Buragadda

Kaur

. Comparison of static and dynamic balance between football and basketball players with chronic ankle instability. Saudi J. Sports Med. 2016; 16(3): 199.

25.

https://www.calculator.net/random-number-generator.html.

26.

Kinovea version 0.8.15, free software under the GPL v2 license, https://www.kinovea.org.

27.

Han

Sung

. Effects of ankle strengthening exercise program on an unstable supporting surface on proprioception and balance in adults with functional ankle instability. J Exerc Rehabil. 2018; 14: 301-5.

28.

Padua

DiStefano

Beutler

de la Motte

DiStefano

Marshall

. The Landing Error Scoring System as a Screening Tool for an Anterior Cruciate Ligament Injury-Prevention Program in Elite-Youth Soccer Athletes. J Athl Train. 2015; 50(6): 589-595.

29.

Zouhal

Abderrahman

Dupont

, et al. Effects of neuromuscular training on agility performance in elite soccer players. Front. Physiol. 2019; 10: 947.

30.

Egesoy

Unver

Uludag

Celik

Burulday

. The Acute Effect of the Application of the Myofascial Release to the Balance, Anaerobic Power and Functional Movements in Young Soccer Players. Amb Sci. 2020; 7: 154-158.

31.

Sakhalkar

Nagulkar

Mahajan

. Effectiveness of myofascial release versus passive stretching on hamstring flexibility in amateur football players-a comparative study. Int J Health Sci Res. 2022.

32.

Pérez-Bellmunt

Casasayas-Cos

Ragazzi

, et al. Foam rolling vs. proprioceptive neuromuscular facilitation stretching in the hamstring flexibility of amateur athletes: control trials. Int. J. Environ. Res. Public Health. 2023; 20(2): 1439.