Does Restricted Ankle Joint Mobility Influence Hamstring Muscle Strength, Work and Power in Football Players after ACL Reconstruction and Non-Injured Players?

This study was aimed at observing how the limitation of ankle dorsiflexion ROM affects hamstring muscle Peak Torque/BW (%), Average Power (W), and Total Work (J), and whether this effect is similar in football players after ACL rupture and reconstruction and in those without injuries. The study included 47 professional football players who were divided into two groups: Group 1 (n = 24) after ACL reconstruction and Group 2 (n = 23) without injuries in the past 3 years. Based on the Weight-Bearing Lunge Test (WBLT), the following subgroups in Groups 1 and 2 were distinguished: N (normal ankle joint dorsiflexion) and R (restricted ankle joint dorsiflexion). The concentric isokinetic test (10 knee flexions and extensions at 60°/s) was performed on both limbs. Significantly lower values of Peak Torque/BW and Average Power were observed in Group 1 compared to Group 2, as well as in subjects with normal and restricted ankle dorsiflexion. However, no significant differences were noted for either group in any of the strength variables comparing subjects with normal and restricted ankle dorsiflexion. A poor and non-significant correlation was exhibited between the ankle joint range of dorsiflexion and all the strength variables. The area under the ROC curve (AUC) for all the evaluated variables in both groups was below 0.5, or very close to this value, indicating that ankle dorsiflexion ROM has no diagnostic accuracy for hamstring muscle strength. Based on the obtained results, it can be assumed that ankle dorsiflexion limitation, which is common in football players, is not a factor in weakening hamstring muscle strength, either in football players after ACL reconstruction or among those without injuries. However, some authors have reported that limited mobility of the ankle joint can have a destructive effect on the work of the lower limbs and may also be a factor in increasing the risk of football injuries in this area. Therefore, we have suggested that hamstring muscle weakness and increased risk of injury may occur due to factors other than limited ankle mobility. These observations may be of great importance in the selection of prevention methods by including a broad spectrum of physical techniques, not just exercises that focus on the improvement of mobility or stability of the lower limbs.

The Evaluation of Asymmetry in Isokinetic and Electromyographic Activity (sEMG) of the Knee Flexor and Extensor Muscles in Football Players after ACL Rupture Reconstruction and in the Athletes following Mild Lower-Limb Injuries.

This study was aimed at evaluating knee stabilizer (quadriceps and hamstring) muscle strength and the medio-lateral symmetry of hamstring fatigue in football players after ACL reconstruction and with mild lower extremity injuries. The study comprised 65 professional football players who were divided into three groups: Group 1 (n = 24; 22.7 ± 3.6 years; 175 ± 4 cm; 77.3 ± 7.6 kg) after ACL reconstruction, Group 2 (n = 21; 20.5 ± 3.7 years; 177 ± 6 cm; 74.3 ± 9.1 kg) with mild lower-limb injuries (grade 1 muscle strains) and Group 3 (n = 20; 23.1 ± 2.8 years; 178 ± 6 cm; 75.8 ± 8.8 kg) without injuries in the past 3 years. The concentric isokinetic test (10 knee flexions and extensions at 60, 180 and 300°/s with a 30 s interval for rest) was performed on both limbs. Fatigue symmetry between the medial and lateral hamstrings was measured with sEMG during 60 s of isometric contractions. In comparison to the other groups, the injured leg demonstrated significantly lower values of peak torque for the quadriceps (G1-G2 = 48%, 38%, 14%; G1-G3 = 49%, 25%, 14%) and hamstring muscles (G1-G2 = 36%, 35%, 18%; G1-G3 = 64%, 28%, 17%) as well as lower values of hamstring muscle work (G1-G2 = 262 J, 157 J; G1-G3 = 219 J, 179 J) and power (G1-G2 = 34 W; 11 W; G1-G3 = 29 W, 12 W). No significant differences were noted in strength between Groups 2 and 3. The significantly higher fatigue of the BF compared to the SEM muscle was seen in Group 1 for the involved (mean difference = 0.12) and uninvolved limbs (mean difference = -0.10), but in Group 2, a non-significant trend towards asymmetry was also noted. No asymmetry in hamstring muscle fatigue was determined in Group 3. The results of our study allow us to indicate that active football players who previously met the RTS criteria, had deficits in lower-limb muscle performance 2-3 years after reconstruction, which could lead to ACL re-injury. This observation is potentially of importance because these deficits may not be subjectively reported by such athletes and also may not be visible in regular orthopedic and physiotherapeutic assessment.

Correction: The influence of cervical spine rehabilitation on bioelectrical activity (sEMG) of cervical and masticatory system muscles.

[This corrects the article DOI: 10.1371/journal.pone.0250746.].

Impact of Cervical Spine Rehabilitation on Temporomandibular Joint Functioning in Patients with Idiopathic Neck Pain.

OBJECTIVE: The aim of this study was to assess the effectiveness of a 3-week rehabilitation programme focusing only on the cervical region, pain intensity, range of motion in the cervical spine, head posture, and temporomandibular joint (TMJ) functioning in subjects with idiopathic neck pain who did not report TMJ pain. DESIGN: A parallel group trial with follow-up. METHODS: The study included 60 participants divided into 2 groups: experimental: n = 25, 27-57 years old, experiencing idiopathic neck pain and who underwent a 3-week rehabilitation programme, and the control, n = 35, 27-47 years, who were cervical pain-free. At baseline and after 3 weeks of treatment in the experimental group and with a 3-week time interval in the control group, pain intensity, head posture in the sagittal plane, range of motion in the cervical spine, and TMJ functioning were evaluated. RESULTS: After 3 weeks of rehabilitation, there was a significant decrease in pain intensity, improved range of motion of the cervical spine and head posture, and improved clinical condition of TMJ in participants with idiopathic neck pain who did not report TMJ pain. CONCLUSION: The study suggested that idiopathic neck pain is associated with limited range of motion in the cervical spine, incorrect head posture, and TMJ dysfunction. Our data suggests that therapy focusing only on the cervical region may improve the clinical condition of the TMJ in subjects with idiopathic neck pain who do not report TMJ pain. These observations could be helpful in physiotherapeutic treatment of neck and craniofacial area dysfunctions. This trial is registered with ISRCTN Registry ISRCTN14511735.

Composite Score of Readiness (CSR) as Holistic Profiling of Functional Deficits in Footballers Following ACL Reconstruction.

BACKGROUND: The decision to return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction is difficult; thus, coaching staff require a readable, easy-to-use, and holistic indication of an athlete's readiness to play. PURPOSE: To present the Composite Score of Readiness (CSR) as a method providing a single score for RTS tests after ACL reconstruction. METHODS: The study comprised 65 male football players (age 18-25 years), divided into three groups: ACL group-subjects after ACL rupture and reconstruction, Mild Injury (MI) group-subjects after mild lower limb injuries, and Control (C) group-subjects without injuries. The CSR was calculated based on three performed tests (Y-balance test, Functional Movement Screen, and Tuck Jump Assessment) and expressed as the sum of z-scores. The CSR index allows highlighting an athlete's functional deficits across tests relative to the evaluated group. RESULTS: The CSR indicated that relative to the group of athletes under the study, similar functional deficits were present. Comparing athletes following ACL reconstruction to both the MI and C groups, in the majority of subjects, the CSR index was below zero. The correlation between CSR and raw tests results indicated that the CSR is most strongly determined by YBT. CONCLUSION: The CSR is a simple way to differentiate people after serious injuries (with large functional deficits) from people without injuries or with only small deficits. Because the CSR is a single number, it allows us to more easily interpret the value of functional deficits in athletes, compared to rating those deficits based on raw tests results.

The influence of cervical spine rehabilitation on bioelectrical activity (sEMG) of cervical and masticatory system muscles.

BACKGROUND: Coexistence of temporomandibular joint discomfort along with cervical spine disorders is quite common, and is associated with many limitations and adverse symptoms for the patient. Both diagnostics and treatment of these ailments are difficult, and in many cases, the effects of therapy are not satisfactory. This study assessed the impact of a 3-week neck-only rehabilitation programme without direct intervention in the craniofacial area on the bioelectric activity of both the cervical spine and muscles in the craniofacial area among patients with idiopathic neck pain who do not report TMJ pain. DESIGN: A parallel group trial with follow-up; Setting: Rehabilitation Clinic. METHODS: Twenty five patients experiencing idiopathic neck pain underwent the 3-week rehabilitation programme. Thirty five age-matched subjects with no cervical spine and temporomandibular joint (TMJ) dysfunctions were control group. At baseline and after 3 weeks the cervical and craniofacial area muscles' bioelectrical activity (sEMG) was evaluated. RESULTS: In the experimental group during cervical flexion, a significant decrease of sEMG amplitude was noted in the right (mean 25.1 µV; 95% CI: 21.5-28.6 vs mean 16.8 µV; 95% CI: 13.8-19.7) and left (mean 25.9 µV; 95% CI: 21.7-30.0 vs mean 17.2 µV; 95% CI: 13.6-20.7) Sternocleidomastoid as well as a significant increase in sEMG amplitude of the right (mean 11.1 µV; 95% CI: 7.9-14.2 vs mean 15.7 µV; 95% CI: 12.1-19.2) and left (mean 15.3 µV; 95% CI: 11.9-18.6 vs mean 20.2 µV; 95% CI: 15.7-24.2) Upper Trapezius muscles. In the experimental group, after therapy right and left Sternocleidomastoid, Temporalis Anterior and Masseter muscles presented lower fatigue levels. CONCLUSIONS: Three weeks of rehabilitation without any therapeutic intervention in temporomandibular joint significantly decreased the bioelectrical activity of the neck and craniofacial muscles while improving the muscle pattern of coactivation in participants with idiopathic neck pain who do not report temporomandibular joint pain. These observations could be helpful in the physiotherapeutic treatment of neck and craniofacial area dysfunctions. TRIAL REGISTRATION: ID ISRCTN14511735-retrospectively registered.

The Reliability of Pelvic Floor Muscle Bioelectrical Activity (sEMG) Assessment Using a Multi-Activity Measurement Protocol in Young Women.

The aim of the study was to determine the between-trial and between-day reliability of the Glazer protocol and our multi-activity surface electromyography (sEMG) measurement protocol for pelvic floor muscle (PFM) evaluation. The bioelectrical activity of PFM was collected using an endovaginal electrode in 30 young, Caucasian, nulliparous women (age 22-27, 168.6 ± 5.1 cm, 57.1 ± 11.8 kg). The between-trial and between-day reliability of the original Glazer protocol and the new multi-activity sEMG protocol were assessed during the following phases: pre-baseline rest, phasic (flick) contractions, tonic contractions, endurance contraction, and post-baseline rest. The Glazer protocol was characterized by poor and moderate measurement reliability. The time-domain parameters for the rise and fall of the signal amplitude and median frequency showed poor between-trial and between-day reliability. The mean and peak amplitudes indicated mainly good between-trial and moderate between-days reliability. Our protocol showed moderate to excellent reliability of both time-domain and quantitative parameters of muscle recruitment. In our protocol, the frequency-domain parameters describing muscle fatigue demonstrated much higher reliability than in the case of the Glazer protocol. The most important information obtained in this study was the significant improvement of diagnostic validity in PFM bioelectrical activity evaluation. The higher reliability of our sEMG protocol compared to original Glazer protocol allowed us to suggest that protocol modifications and changes in sEMG signal processing methods were effective in the improvement of PFM assessment quality. The new parameters calculated from the sEMG signal proposed in our sEMG protocol allowed us to obtain additional clinically important information about PFM dysfunctions regarding specific deficits of muscle contraction such as decrease in muscle strength; endurance or coordination related to, e.g., stress urinary incontinence; or pelvic floor muscle imbalance after childbirth.

Standard RTS criteria effectiveness verification using FMS, Y-balance and TJA in footballers following ACL reconstruction and mild lower limb injuries.

The anterior cruciate ligament (ACL) is the most frequently injured knee ligament. In previous studies, it was demonstrated that patients following ACL reconstruction may present motor deficits which may be related to increased risk of injury. The objective of the study was to determine whether players who have passed RTS assessment still have deficits in movement patterns or in neuromuscular control after such a serious injury as ACL rupture and reconstruction,. Sixty-five male football players (age 18-25 years), recruited from regional teams, were divided into three groups: (1) ACL group-subjects after ACL rupture and reconstruction (n = 24); (2) Mild Injury (MI) group-subjects after mild lower limb injuries (n = 21); and (3) Control (C) group-subjects without injuries (n = 20). For all groups, the Y-balance test, Functional Movement Screen (FMS) and Tuck Jump Assessment (TJA) were performed. For the Y-balance test in ACL group for the injured leg, significantly lower values were demonstrated for anterior reach ((ACL) 69.2 ± 5.7% vs. (MI) 74.8 ± 4.5% vs. (C) 74.0 ± 5.6%), at posterior-lateral reach ((ACL) 103.2 ± 6.4% vs. (C) 108.5 ± 6.0%) and composite score ((ACL) 93.9 ± 4.4% vs. (MI) 97.9 ± 4.3%) in comparison to the remaining two groups. In the FMS test, the ACL group had significantly lower composite score (12 ± 4 points) compared to the C group (15 ± 2 points). Also, compared to the remaining groups, subjects following ACL reconstruction demonstrated significantly lower performance in the TJA test related to the following elements: thighs do not reach parallel, thighs not equal side-to-side, foot placement not shoulder width apart, technique declines prior to 10 s and lower extremity valgus at landing. The authors have observed that athletes after ACL reconstruction still have deficits in movement patterns or in neuromuscular control despite passing the RTS and being cleared to perform sports. Creating a set of sufficiently sensitive assessment methods may significantly reduce the potential risk of injury due to the fact that diagnosed and monitored deficits may be treated on an ongoing basis. The authors suggest that individual elements of the Y-balance and TJA tests may be suitable for such specific assessment.

Normative values for Glazer Protocol in the evaluation of pelvic floor muscle bioelectrical activity.

The aim of the study was to evaluate pelvic floor muscle bioelectrical activity in healthy, young, and nulliparous women, and to present normative values for all phases and parameters measured with the Glazer Protocol.In this study, 96 healthy, young, nulliparous women (age 22-27 years; 168.6 ±â€Š5.1 cm; 57.1 ±â€Š11.8 kg) were tested. The bioelectrical activity of the pelvic floor muscles was collected using an endovaginal electrode with the Glazer Protocol, which included the following series of muscles contractions and relaxations: pre-baseline rest, phasic contractions, tonic contractions, isometric contractions for muscle endurance evaluation, and post-baseline rest.The following normative values of the bioelectrical signal for all phases of the Glazer Protocol were calculated: mean, minimal, and maximal values, 95% confidence interval, standard deviation, 95% standard deviation confidence interval, variance, coefficient of variation, and standard error of measurement. Average Mean Amplitude (µV) was as follows: pre-baseline rest (6.26 ±â€Š3.33 µV), phasic contractions (49.76 ±â€Š26.44 µV), tonic contractions (37.05 ±â€Š25.99 µV), endurance contraction (16.10 ±â€Š6.68 µV), and post-baseline rest (6.93 ±â€Š3.99 µV).This study was the first in which normative values for all phases of the Glazer Protocol were reported. This protocol is very often used in electromyography devices as a tool for pelvic floor muscle assessment. Due to the fact that the interpretation of the pelvic floor muscle evaluation is complex and difficult, the authors believe that the normative values proposed in this study allow for comprehensive interpretation of this test (both qualitatively and quantitatively) and provide a reference point for parameters measured in women with different pelvic floor dysfunctions.

The association between high-arched feet, plantar pressure distribution and body posture in young women.

The aim of this study was to examine the effect of excessive feet arching (symmetrical and asymmetrical) on plantar pressure distribution and on the alignment of pelvis, spine and shoulder girdle. Eighty-one women (20-40 years old, 61 +/- 12 kg, 165 +/- 5 cm) were divided into 3 groups based on the foot arch index (Group 1 - with normally arched feet, Group 2 with one foot properly arched and the other high-arched, Group 3 with both feet high-arched). Plantar pressure distribution between the right and left foot for the forefoot, midfoot and rearfoot, respectively and body posture were assessed. A slight increase in longitudinal arch of the foot caused changes in the distribution of feet loads both between limbs and between the forefoot and rearfoot and also influenced the whole body. Asymmetrical high-arching of the feet resulted in asymmetry of lower limb load and in the height of the shoulder girdle. We have suggested that any alteration of the foot arch may be harmful to body tissues and should not be considered as correct. Due to the fact that slight increases in longitudinal arch of the foot are very common, they should be considered as a foot defect, and appropriate corrective exercises should be used to prevent forefoot overload and alterations in body posture.

The influence of pelvis reposition exercises on pelvic floor muscles asymmetry: A randomized prospective study.

OBJECTIVE: The assessment of pelvis reposition exercise efficacy in the treatment of pelvic floor muscles (PFM) asymmetry. The hypothesis was that PFM asymmetry may have a functional reason related to lumbopelvic complex misalignment. DESIGN: A parallel group trial with follow-up METHODS:: Thirty young women were divided into 2 groups: experimental (n = 15) and control (n = 15). In experimental group one, a 15-minute trial of pelvis reposition exercise was carried out. Ober test, the Thomas test, and transabdominal PFM ultrasound measurements were performed in both groups. RESULTS: In the experimental group both the Ober and Thomas tests were positive at baseline in most subjects. After the exercise, improvement was noted in Ober test (P = .005; d = 0.75 on the right side, P = .005; d = 0.78 on the left side) and in the Thomas test (P = .005; d = 0.66 on the right side, P = .005; d = 0.67 on the left side). At baseline, the ultrasonographic evaluation of PFM performed during resting and during voluntary pelvic muscles contraction showed the right-left length asymmetry. The return of symmetrical PFM work after pelvis reposition exercise was observed in the experimental group. There were no statistically significant changes in the control group.s CONCLUSIONS:: We suggest that after reposition exercises, the pelvis was more symmetrically aligned in relation to body axis; therefore, the muscles of the pelvic floor have functional length and did not shorten or lengthen due to pelvis rotation. In this study, for the first time, it was presented that PFM asymmetry visible in ultrasonography may be corrected by this specific exercise. Further analysis of the causes of this asymmetry may lead to more accurate treatment of PFM dysfunctions.

Effects of Exoskeleton Gait Training on Balance, Load Distribution, and Functional Status in Stroke: A Randomized Controlled Trial.

Background: As a result of stroke, patients have problems with locomotion and transfers, which lead to frequent falls. Recovery after stroke is a major goal of rehabilitation, but it is difficult to choose which treatment method is most beneficial for stroke survivors. Recently, powered robotic exoskeletons are used in treatment to maximize the neural recovery of patients after stroke, but there are no studies evaluating the changes in balance among patients rehabilitated with an exoskeleton. Purpose: The aim of this study was to evaluate the effects of Ekso GT exoskeleton-assisted gait training on balance, load distribution, and functional status of patients after ischemic stroke. Methods: The outcomes are based on 44 patients aged 55-85 years after ischemic stroke who were previously randomly assigned into two groups: experimental (with Ekso GT rehabilitation) and control (with classical rehabilitation). At baseline and after 4 weeks of treatment, the patients were evaluated on balance, load distribution, and functional status using, respectively a stabilometric platform, the Barthel Index, and the Rivermead Mobility Index. Results: In the experimental group, balance improved regarding the variables describing sway area as ellipse major and minor axes. In the control group, improvement was noted in sway velocity. After the therapy, total load distribution on feet in both groups showed a small and insignificant tendency toward reduction in the amount of uninvolved limb loading. In the control group, significant load transfer from the backfoot to the forefoot was noted. Both forms of rehabilitation caused significant changes in functional status. Conclusions: Both training with the use of the Ekso GT exoskeleton and classical physiotherapy lead to functional improvement of patients after ischemic stroke. However, in the experimental group, improvement was observed in a larger number of categories, which may suggest potentially greater impact of treatment with the exoskeleton on functional status. Also, both forms of rehabilitation caused significant changes in balance, but we have noted some trends indicating that treatment with exoskeleton may be more beneficial for some patients. The load transfer from the backfoot to the forefoot observed in the control group was an unfavorable phenomenon. We suggest that the Ekso GT exoskeleton may be a promising tool in the rehabilitation of patients after stroke. Trial registration: Trial ID ACTRN12616000148471.

The influence of high- and low-heeled shoes on balance in young women.

PURPOSE: To evaluate the influence of two different heel heights on static balance and on limits of stability during functional reach test, with both the eyes open and eyes closed, in young women (age 22-27) who did not wear heeled shoes habitually. METHODS: Thirtyone young women (age 22-27) performed balance tests on a stabilometric platform without footwear and in shoes with 4 cm and 10 cm heels. The center of pressure (COP) deviations range and velocity in anteroposterior (AP) and mediolateral (ML) directions were assessed. The limits of stability were measured when the subject leaned the body in sagittal plane. RESULTS: The ranges of COP deviations in AP and ML directions were already significantly higher in 4 cm heels in comparison to the barefoot condition. COP deviation velocity significantly raised with increasing heel height as well as when the eyes were closed. CONCLUSIONS: A more pronounced increase of COP deviation velocity than COP deviation range when measurement conditions become more difficult may indicate that young women anticipate postural corrections by stimulation of ankle proprioception when heeled shoes are worn. High-heeled shoes may lead to alterations in velocity feedback balance mechanism, which may increase the risk of musculoskeletal injuries. Observed in our study adverse effect of heeled footwear on balance may predispose women to falls and injuries. Permanent use of stiletto high heels should be avoided by women.

Comparison of Two Different Modes of Active Recovery on Muscles Performance after Fatiguing Exercise in Mountain Canoeist and Football Players.

BACKGROUND: The aim of this study is to assess if the application of different methods of active recovery (working the same or different muscle groups from those which were active during fatiguing exercise) results in significant differences in muscle performance and if the efficiency of the active recovery method is dependent upon the specific sport activity (training loads). DESIGN: A parallel group non-blinded trial with repeated measurements. METHODS: Thirteen mountain canoeists and twelve football players participated in this study. Measurements of the bioelectrical activity, torque, work and power of the vastus lateralis oblique, vastus medialis oblique, and rectus femoris muscles were performed during isokinetic tests at a velocity of 90°/s. RESULTS: Active legs recovery in both groups was effective in reducing fatigue from evaluated muscles, where a significant decrease in fatigue index was observed. The muscles peak torque, work and power parameters did not change significantly after both modes of active recovery, but in both groups significant decrease was seen after passive recovery. CONCLUSIONS: We suggest that 20 minutes of post-exercise active recovery involving the same muscles that were active during the fatiguing exercise is more effective in fatigue recovery than active exercise using the muscles that were not involved in the exercise. Active arm exercises were less effective in both groups which indicates a lack of a relationship between the different training regimens and the part of the body which is principally used during training.