Correlations between physical activity and quality of life in entrepreneurs from Wroclaw, Poland.

BACKGROUND: Limited physical activity is one of the main reasons for the rapid increase in the prevalence of diseases of affluence, which can lead to premature deaths in adults. Quality of life may be one of potential determinants of physical activity. The aim of this article is to identify the relationships between physical activity and quality of life in entrepreneurs from Wroclaw, Poland. METHODS: A cross-sectional study was conducted on a group of 616 entrepreneurs (216 women and 400 men). A diagnostic survey method was used with a direct interview technique. The research tools included the International Physical Activity Questionnaire Short Form and the World Health Organization Quality of Life Questionnaire. RESULTS: Among the studied entrepreneurs, along with their higher ratings of overall quality of life, the odds of high rather than low levels of physical activity increased nearly fivefold (OR 4.86, CI 3.34-7.07). Entrepreneurs with higher assessment levels of their perceived health condition were nearly twice as likely to report high rather than low physical activity levels (OR 1.92, CI 1.42-2.59). The conditional probability of high rather than low levels of physical activity also increased in the entrepreneurs with higher assessments of quality of life in the physical, psychological, social, and environmental domains, by 34%, 11%, 5%, and 6%, respectively. CONCLUSION: Programs promoting physical activity among entrepreneurs, which focus on moderate and high intensity exercise, should be considered desirable in the context of the study findings. Activities aimed at improving quality of life in the physical and psychological domains as a potential determinant of the level of physical activity of entrepreneurs are also worth recommending.

Repeatability of the Vibroarthrogram in the Temporomandibular Joints.

Current research concerning the repeatability of the joint's sounds examination in the temporomandibular joints (TMJ) is inconclusive; thus, the aim of this study was to investigate the repeatability of the specific features of the vibroarthrogram (VAG) in the TMJ using accelerometers. The joint sounds of both TMJs were measured with VAG accelerometers in two groups, study and control, each consisting of 47 participants (n = 94). Two VAG recording sessions consisted of 10 jaw open/close cycles guided by a metronome. The intraclass correlation coefficient (ICC) was calculated for seven VAG signal features. Additionally, a k-nearest-neighbors (KNN) classifier was defined and compared with a state-of-the-art method (joint vibration analysis (JVA) decision tree). ICC indicated excellent (for the integral below 300 Hz feature), good (total integral, integral above 300 Hz, and median frequency features), moderate (integral below to integral above 300 Hz ratio feature) and poor (peak amplitude feature) reliability. The accuracy scores for the KNN classifier (up to 0.81) were higher than those for the JVA decision tree (up to 0.60). The results of this study could open up a new field of research focused on the features of the vibroarthrogram in the context of the TMJ, further improving the diagnosing process.

Heightened tone and stiffness with concurrent lowered elasticity of peroneus longus and tibialis anterior muscles in athletes with chronic ankle instability as measured by myotonometry.

In a recent study, myotonometry revealed adverse alterations in the mechanical properties of ankle periarticular muscles in soldiers reporting previous lateral ankle sprain (LAS) incidents. This knowledge, if confirmed in athletes with developed chronic ankle instability (CAI), may have important diagnostic and therapeutic implications in sports medicine and rehabilitation. Consequently, the purpose of the study was to explore mechanical properties of the peroneus longus (PL), tibialis anterior (TA), and the lateral and medial gastrocnemius (LG and MG, respectively) muscles in athletes suffering CAI. Fourteen adult male athletes with developed CAI (International Ankle Consortium selection criteria) and 15 healthy male athletes without any LAS incidence as the control group (CO) participated in the study. The CAI and CO groups were characterized by similar anthropometric parameters and weekly training volume. In both the groups of athletes, we performed resting state (controlled with electromyographic recordings) myotonometric measurements (using a MyotonPRO® device) in the PL, TA, LG and MG muscles and calculated the following five myotonometric parameters: frequency (F-MYO), stiffness (S-MYO), decrement (d-MYO), relaxation time (R-MYO) and creep (C-MYO). Athletes from the CAI group (compared to the CO group) exhibited significantly higher values of F-MYO and S-MYO as well as lower values of R-MYO and C-MYO in the PL and TA muscles. No significant inter-group differences were found in the remaining myotonometric parameters. Using myotonometry, our study is the first to reveal that athletes with developed CAI are characterized by heightened tone and stiffness with concurrent lowered elasticity of the PL and TA muscles.

Using Nonlinear Vibroartrographic Parameters for Age-Related Changes Assessment in Knee Arthrokinematics.

Changes in articular surfaces can be associated with the aging process and as such may lead to quantitative and qualitative impairment of joint motion. This study is aiming to evaluate the age-related quality of the knee joint arthrokinematic motion using nonlinear parameters of the vibroarthrographic (VAG) signal. To analyse the age-related quality of the patellofemoral joint (PFJ), motion vibroarthrography was used. The data that were subject to analysis represent 220 participants divided into five age groups. The VAG signals were acquired during flexion/extension knee motion and described with the following nonlinear parameters: recurrence rate (RR) and multi-scale entropy (MSE). RR and MSE decrease almost in a linear way with age (main effects of group p<0.001; means (SD): RR=0.101(0.057)−0.020(0.017); and MSE=20.9(8.56)−13.6(6.24)). The RR post-hoc analysis showed that there were statistically significant differences (p<0.01) in all comparisons with the exception of the 5th−6th life decade. For MSE, statistically significant differences (p<0.01) occurred for: 3rd−7th, 4th−7th, 5th−7th and 6th life decades. Our results imply that degenerative age-related changes are associated with lower repeatability, greater heterogeneity in state space dynamics, and greater regularity in the time domain of VAG signal. In comparison with linear VAG measures, our results provide additional information about the nature of changes of the vibration dynamics of PFJ motion with age.

Muscle activation time and free-throw effectiveness in basketball.

This study attempts to analyze the relationship between free-throw efficiency and the time of arm muscle activation in players from 3 basketball teams with different levels of experience was investigated. During the experiment each player made 20 free throws during which the activation time of his right and left biceps and triceps brachii muscles were measured with the use of surface electromyography and high-speed cameras. Significant differences in muscle activation time (t) during a free throw were found between the groups of basketball players (p = 0.038) (novices: t = 0.664 ± 0.225 s, intermediate-level players: t = 1.15 ± 0.146 s, experts: t = 1.01 ± 0.388 s). In the right triceps brachii muscle in expert basketball players the coefficient of variation (CV) amounted to 44.60% at 81% efficiency, and in novices to 27.12% at 53% efficiency. The time of arm muscle activation during a free throw and its fluctuations vary along with the training experience of basketball players. In all studied groups of players, the variability of muscle activation time in accurate free throws is greater than in inaccurate free throws. Free-throw speed is irrelevant for free-throw efficiency.

Caffeine-Induced Effects on Human Skeletal Muscle Contraction Time and Maximal Displacement Measured by Tensiomyography.

Studies on muscle activation time in sport after caffeine supplementation confirmed the effectiveness of caffeine. The novel approach was to determine whether a dose of 9 mg/kg/ body mass (b.m.) of caffeine affects the changes of contraction time and the displacement of electrically stimulated muscle (gastrocnemius medialis) in professional athletes who regularly consume products rich in caffeine and do not comply with the caffeine discontinuation period requirements. The study included 40 professional male handball players (age = 23.13 ± 3.51, b.m. = 93.51 ± 15.70 kg, height 191 ± 7.72, BMI = 25.89 ± 3.10). The analysis showed that in the experimental group the values of examined parameters were significantly reduced (p ≤ 0.001) (contraction time: before = 20.60 ± 2.58 ms/ after = 18.43 ± 3.05 ms; maximal displacement: before = 2.32 ± 0.80 mm/after = 1.69 ± 0.51 mm). No significant changes were found in the placebo group. The main achievement of this research was to demonstrate that caffeine at a dose of 9 mg/kg in professional athletes who regularly consume products rich in caffeine has a direct positive effect on the mechanical activity of skeletal muscle stimulated by an electric pulse.

Effects of Viscosupplementation on Quality of Knee Joint Arthrokinematic Motion Analyzed by Vibroarthrography.

OBJECTIVE: To evaluate the influence of viscosupplementation on osteoarthritic knee arthrokinematics analyzed by VAG. It is considered that intra-articular hyaluronic acid injection may improve the function of synovial joints by recovery of friction-reducing properties of articular environment. DESIGN: Thirty-five patients with knee osteoarthritis (grade II according to the Kellgren-Lawrence system) and 50 asymptomatic subjects were enrolled in the study. Patients were analyzed at 3 time points: 1 day before and 2 weeks and 4 weeks after single injection of 1.5% cross-linked hyaluronate. Control subjects were tested once. The vibroarthrographic signals were collected during knee flexion/extension motion using an accelerator and described by variation of mean square (VMS), mean range (R5), and power spectral density for frequency of 50 to 250 Hz (P1), and 250 to 450 Hz (P2). RESULTS: Patients before viscosupplementation were characterized by about 2-fold higher values of vibroarthrographic parameters than controls. Two weeks after the procedure, the values of R5, P1, and P2 significantly decreased, in comparison to pre-injection. At 4 weeks post-injection, we noted a significant increase in R5, P1, and P2 values, when compared to 2 weeks post-injection. Finally, at 4 weeks post-injection, the level of VMS, R5, and P2 parameters did not differ from values obtained at pre-injection. CONCLUSIONS: We showed that viscosupplementation may be effective in providing arthrokinematics improvement, but with a relatively short period of duration. This phenomenon is observed as decreased vibroacoustic emission, which reflects a more smooth movement in the joint.

Vibroarthrographic analysis of patellofemoral joint arthrokinematics during squats with increasing external loads.

BACKGROUND: The patellofemoral joint (PFJ) provides extremely low kinetic friction, which results in optimal arthrokinematic motion quality. Previous research showed that these friction-reducing properties may be diminished due to the increase in articular contact forces. However, this phenomenon has not been analyzed in vivo during functional daily-living activities. The aim of this study was the vibroarthrographic assessment of changes in PFJ arthrokinematics during squats with variated loads. METHODS: 114 knees from 57 asymptomatic subjects (23 females and 34 males) whose ages ranged from 19 to 26 years were enrolled in this study. Participants were asked to perform 3 trials: 4 repetitions of bodyweight squats (L0), 4 repetitions of 10 kg barbell back loaded squats (L10), 4 repetitions of 20 kg barbell back loaded squats (L20). During the unloaded and loaded (L10, L20) squats, vibroarthrographic signals were collected using an accelerometer placed on the patella and were described by the following parameters: variation of mean square (VMS), mean range (R4), and power spectral density for frequency of 50-250 Hz (P1) and 250-450 Hz (P2). RESULTS: Obtained results showed that the lowest values were noted in the unloaded condition and that the increased applied loads had a significant concomitant increase in all the aforementioned parameters bilaterally (p < 0.05). CONCLUSION: This phenomenon indicates that the application of increasing knee loads during squats corresponds to higher intensity of vibroacoustic emission, which might be related to higher contact stress and kinetic friction as well as diminished arthrokinematic motion quality.

Vibroarthrographic Signal Spectral Features in 5-Class Knee Joint Classification.

Vibroarthrography (VAG) is a non-invasive and potentially widely available method supporting the joint diagnosis process. This research was conducted using VAG signals classified to five different condition classes: three stages of chondromalacia patellae, osteoarthritis, and control group (healthy knee joint). Ten new spectral features were proposed, distinguishing not only neighboring classes, but every class combination. Additionally, Frequency Range Maps were proposed as the frequency feature extraction visualization method. The results were compared to state-of-the-art frequency features using the Bhattacharyya coefficient and the set of ten different classification algorithms. All methods evaluating proposed features indicated the superiority of the new features compared to the state-of-the-art. In terms of Bhattacharyya coefficient, newly proposed features proved to be over 25% better, and the classification accuracy was on average 9% better.

Effect of a Six-Week Intermittent Fasting Intervention Program on the Composition of the Human Body in Women over 60 Years of Age.

The objective of this research was to determine the effectiveness of intermittent fasting (IF) in reducing body fat and lowering body mass index. An additional objective was to determine the feasibility of applying IF in overweight women over 60 years of age, which was assessed by the ratio of subjects who resigned from the diet plan. This study included a group of 45 women over 60 years of age. The intervention in the experimental group involved complete abstinence from food intake for 16 h per day, from 20:00 p.m. to 12:00 a.m. (the next day). The results demonstrated that the body weight in the subjects in the experimental group (EXP) group decreased by almost 2 kg and this decrease was visible in the remaining parameters related to body fat mass. The skeletal muscle mass did not change significantly, which indicates an actual decrease in the fat mass. The proportion of subjects who did not succeed in following the prescribed diet plan was 12%. The application of intermittent fasting in female subjects over 60 years of age resulted in positive changes in body composition. Time-restricted feeding (TRF) was characterized by a lower resignation rate compared to other diets involving intermittent fasting.

Effects of Immobilization and Re-Mobilization on Knee Joint Arthrokinematic Motion Quality.

BACKGROUND: Knee immobilization is a common intervention for patients with traumatic injuries. However, it usually leads to biomechanical/morphological disturbances of articular tissues. These changes may contribute to declining kinetic friction-related quality of arthrokinematics; however, this phenomenon has not been analyzed in vivo and remains unrecognized. Thus, the aim of the present study is to investigate the effect of immobilization and subsequent re-mobilization on the quality of arthrokinematics within the patellofemoral joint, analyzed by vibroarthrography (VAG). METHODS: Thirty-four patients after 6-weeks of knee immobilization and 37 controls were analyzed. The (VAG) signals were collected during knee flexion/extension using an accelerometer. Patients were tested on the first and last day of the 2-week rehabilitation program. RESULTS: Immobilized knees were characterized by significantly higher values of all VAG parameters when compared to controls (p < 0.001) on the first day. After 2 weeks, the participants in the rehabilitation program that had immobilized knees showed significant improvement in all measurements compared to the baseline condition, p < 0.05. However, patients did not return to normal VAG parameters compared to controls. CONCLUSION: Immobilization-related changes within the knee cause impairments of arthrokinematic function reflected in VAG signal patterns. The alterations in joint motion after 6 weeks of immobilization may be partially reversible; however, the 2-week physiotherapy program is not sufficient for full recovery.

Analysis of patellofemoral arthrokinematic motion quality in open and closed kinetic chains using vibroarthrography.

BACKGROUND: Knee movements performed in open (OKC) and closed (CKC) kinetic chains generate various patterns of muscle activities and especially distinct contact stresses in the patellofemoral joint (PFJ). In contrast to these features, the arthrokinematic motion quality (AMQ) of the PFJ has not been compared between mentioned conditions. In this study we performed vibroarthrographic analysis of AMQ in movements performed in OKC and CKC, in healthy subjects and individuals with chondromalacia patellae, to assess which of the test conditions is more efficient in differentiation between healthy and deteriorated joints. Moreover, our analysis will broaden the knowledge related to behavior of normal and pathological synovial joints during motion with and without weight bearing. It is an essential issue, due to the recently observed significant interest in comparing potential benefits and limitations of CKC and OKC exercises as they relate to lower extremity rehabilitation. METHODS: 100 subjects (62 healthy controls and 38 subjects with PFJ chondromalacia) were enrolled. During repeated knee flexion/extension motions performed in OKC (in a sitting position) and CKC (sit-to-stand movements), the vibroarthrographic signals were collected using an accelerometer and described by variability (VMS), amplitude (R4), and spectral power in 50-250 Hz (P1) and 250-450 Hz (P2) bands. RESULTS: Significant differences in VMS [V], R4 [V], P1 [V2/Hz] and P2 [V2/Hz] between OKC and CKC were found (0.0001, 0.969. 0.800 0.041 vs 0.013, 3.973, 6.790, 0.768, respectively, P < 0.001). Moreover, in both analyzed load-related conditions the subjects with chondromalacia were characterized by significantly higher values of all parameters, when compared to controls (P < 0.001), with effect size values over 0.6. CONCLUSIONS: We showed that motion of the physiological, unloaded PFJ articular surfaces in OKC is nearly vibrationless, which corresponds with optimal AMQ of PFJ, while loaded movements in CKC are characterized by a higher vibroacoustic emission level. Moreover, chondral lesions should be considered as an increased friction-related, aggravating factor of AMQ, which is critical in CKC movements under load. Nonetheless, OKC and CKC conditions are characterized by large effect sizes, and provide an efficient test frame for differentiating physiological knees and joints with chondral lesions.

Gait and functional status analysis before and after total knee arthroplasty.

BACKGROUND: Among the procedures for severe gonarthrosis, total knee arthroplasty (TKA) is considered a successful method patient satisfaction and functional improvement; however, TKA is commonly associated with incompletely recovered gait function. The aim of this study was to evaluate the influence of TKA and physiotherapy programmes on gait features and patient-reported functional status and the relationship between them, leading to broader knowledge of the origins of long-term gait disturbances. METHODS: Walking speed, step length and single support time were analysed by GAITRite system in 60 healthy controls and 21 TKA patients analysed at four time points: one day before and five days after surgery and before and after a three-week rehabilitation (12 and 15 weeks after surgery). Functional status was assessed using the Western Ontario and McMaster Osteoarthritis Index (WOMAC). RESULTS: At all time points, the TKA subjects walked significantly slower than the controls, but walking speed continuously increased after surgery. Gait asymmetries were observed in single support time (before surgery) and step length (after surgery). Partial restoration of gait function was observed 12 weeks after surgery and completion of the rehabilitation programme. An indirect correlation between gait velocity and function WOMAC subscores was found. CONCLUSIONS: Patients after TKA were characterised by significant improvements in self-reported functionality and progressive reduction of gait abnormalities, probably related to pain reduction. However, at 15 weeks after surgery, patients exhibited step length asymmetry, which could be considered as an effect of habits of three-point crutch gait in the early postoperative period.

Age-related changes in shock absorption capacity of the human spinal column.

BACKGROUND: The spinal column possesses shock absorption properties, mainly provided by the intervertebral discs. However, with the process of senescence, all structures of the spine, including the discs, undergo degenerative changes. It may lead to alteration of the mechanical properties of the spinal motion segment and diminished capacity for vibration attenuation. OBJECTIVE: The objective of this study was to investigate the age-related changes in shock absorption properties of the spine. PATIENTS AND METHODS: A total of 112 individuals divided into three groups according to age (third, fifth, and seventh decades of life) were enrolled in this study. The transmissibility of vibrations through the spine was measured in a standing position on a vibration platform by accelerometers mounted at the levels of S2 and C0. Registered signals were described using four parameters: VMS (variability), peak-to-peak amplitude (PPA), and spectral activity in two bands F2 (0.7-5 Hz) and F20 (15-25 Hz). RESULTS: In all age groups, signals registered at C0 were characterized by significantly lower values of VMS, PPA, and F20, when compared to level S2. Simultaneously, the parameter F20 significantly differed among all age groups when C0 vibrations were analyzed: 2.43±1.93, 5.02±3.61, and 10.84±5.12 for the third, fifth, and seventh decades of life, respectively. CONCLUSION: The human spinal column provides vibration attenuation; however, this property gradually declines with the aging process.

Analysis and multiclass classification of pathological knee joints using vibroarthrographic signals.

BACKGROUND AND OBJECTIVE: Vibroarthrography (VAG) is a method developed for sensitive and objective assessment of articular function. Although the VAG method is still in development, it shows high accuracy, sensitivity and specificity when comparing results obtained from controls and the non-specific, knee-related disorder group. However, the multiclass classification remains practically unknown. Therefore the aim of this study was to extend the VAG method classification to 5 classes, according to different disorders of the patellofemoral joint. METHODS: We assessed 121 knees of patients (95 knees with grade I-III chondromalacia patellae, 26 with osteoarthritis) and 66 knees from 33 healthy controls. The vibroarthrographic signals were collected during knee flexion/extension motion using an acceleration sensor. The genetic search algorithm was chosen to select the most relevant features of the VAG signal for classification. Four different algorithms were used for classification of selected features: logistic regression with automatic attribute selection (SimpleLogistic in Weka), multilayer perceptron with sigmoid activation function (MultilayerPerceptron), John Platt's sequential minimal optimization algorithm implementation of support vector classifier (SMO) and random forest tree (RandomForest). The generalization error of classification algorithms was evaluated by stratified 10-fold cross-validation. RESULTS: We obtained levels of accuracy and AUC metrics over 90%, more than 93% sensitivity and more than 84% specificity for the logistic regression-based method (SimpleLogistic) for a 2-class classification. For the 5-class method, we obtained 69% and 90% accuracy and AUC respectively, and sensitivity and specificity over 91% and 69%. CONCLUSIONS: The results of this study confirm the high usefulness of quantitative analysis of VAG signals based on classification techniques into normal and pathological knees and as a promising tool in classifying signals of various knee joint disorders and their stages.

Effects of Viscosupplementation on Knee Joint Arthrokinematics - Pilot Study.

BACKGROUND: Osteoarthritis is one of the most common dysfunctions of the musculoskeletal system and viscosup-plementation is becoming an increasingly popular treatment in OA. However, current knowledge regarding biomechanical changes in synovial joints reveals many discrepancies. Therefore, the aim of our study was to evaluate the effect of visco-supplementation on knee joint arthrokinematics as analyzed by vibroarthrography. MATERIAL AND METHODS: Seventeen individuals diagnosed with moderate knee osteoarthritis (VSC) were examined before and after a single injection of hyaluronate. A control group consisted of 30 asymptomatic individuals. During alter-nating extension/flexion of the knee joint, a 6-second vibroarthrographic signal was recorded using an accelerometer. The following parameters were calculated: variance (VMS), amplitude (R4), and spectral power density in the 50-250 Hz (P1) and 250-450 Hz (P2) bands. RESULTS: Statistical analysis showed significant differences (p<0.05) in the values of R4 and P2, which were higher in the VSC group than among the controls. After viscosupplementation, the values of R4, P1 and P2 in the VSC group de-creased to a level not significantly different from that seen among the controls. CONCLUSIONS: 1. After a single intra-articular HA injection, joint motion-related vibrations were reduced, which was recorded as a decreased intensity of vibroacoustic emission. 2. This suggests that the use of viscosupplementation in pa-tients with moderate knee osteoarthritis may improve qualitative aspects of arthrokinematics.

Subjective and Objective Evaluation of the Functional Condition after a Single Lateral Sprain of the Ankle in Athletes.

BACKGROUND: Ankle sprains can lead to functional deficits. However, few papers have investigated deficits following a single lateral ankle sprain as either assessed subjectively by the patient (e.g., with questionnaires) or measured objectively (e.g., by evaluation of postural stability). This paper aims to provide subjective and objective assessment of functional status in athletes after a single lateral ankle sprain. MATERIAL AND METHODS: A lateral ankle sprain group (LAS) consisted of 20 athletes after a single lateral ankle sprain (mean age 23 ± 1.78 years). A control group (CTRL) comprised 20 athletes with no history of injury (mean age 22.5 ± 2.67 years). Subjective assessment was based on the Foot and Ankle Disability Index questionnaire (FADI-Q). A Biodex Balance System SD dynamic platform was used to assess postural stability. Static and dynamic testing was performed in single-leg stance. RESULTS: Statistically significant differences were noted during the comparison of the LAS and CTRL groups in FADI-Q in the following parts: FADI (p=0,017) and FADI TOTAL (p=0,049). Moreover, statistically significant differences were noted in the LAS group between subjects with instability (N-STAB) and without instability (STAB) of the ankle in the parts FADI (p=0,006), FADI SPORT (p=0,011) and FADI TOTAL (p=0,002). During static and dynamic postural stability testing, no significant differences were found between sprained and healthy limbs, between the LAS and CTRL groups, or between the STAB and N-STAB groups. CONCLUSIONS: 1. Athletes after ankle sprain assessed their functio-nal status as worse compared to the control group. Moreover, deterioration in functional status was perceived by athletes with an unstable ankle joint compared to participants with a stable ankle joint. 2. The study indicates that a single ankle sprain is associated with a high risk of developing functio-nal instability. 3. The process of maintaining postural stability was similar in athletes after a single ankle sprain and in those without a history of ankle injury.

Assessment of Relationships Between Joint Motion Quality and Postural Control in Patients With Chronic Ankle Joint Instability.

Study Design Controlled laboratory study, cross-sectional. Background Lateral ankle sprains are among the most common injuries encountered during athletic participation. Following the initial injury, there is an alarmingly high risk of reinjury and development of chronic ankle instability (CAI), which is dependent on a combination of factors, including sensorimotor deficits and changes in the biomechanical environment of the ankle joint. Objective To evaluate CAI-related disturbances in arthrokinematic motion quality and postural control and the relationships between them. Methods Sixty-three male subjects (31 with CAI and 32 healthy controls) were enrolled in the study. For arthrokinematic motion quality analysis, the vibroarthrographic signals were collected during ankle flexion/extension motion using an acceleration sensor and described by variability (variance of mean squares [VMS]), amplitude (mean of 4 maximal and 4 minimal values [R4]), and frequency (vibroarthrographic signal bands of 50 to 250 Hz [P1] and 250 to 450 Hz [P2]) parameters. Using the Biodex Balance System, single-leg dynamic balance was measured by overall, anteroposterior, and mediolateral stability indices. Results Values of vibroarthrographic parameters (VMS, R4, P1 and P2) were significantly higher in the CAI group than those in the control group (P<.01). Similar results were obtained for all postural control parameters (overall, anteroposterior, and mediolateral stability indices; P<.05). Moreover, correlations between the overall stability index and VMS, and P1 and P2, as well as between the anteroposterior stability index and P1 and P2, were observed in the CAI patient group, but not in controls. Conclusion In patients with CAI, deficits in both quality of ankle arthrokinematic motion and postural control were present. Therefore, physical therapy interventions focused on improving ankle neuromuscular control and arthrokinematic function are necessary in CAI patient care. J Orthop Sports Phys Ther 2017;47(8):570-577. Epub 4 Nov 2016. doi:10.2519/jospt.2017.6836.

Joint Motion Quality in Chondromalacia Progression Assessed by Vibroacoustic Signal Analysis.

BACKGROUND: Because of the specific biomechanical environment of the patellofemoral joint, chondral disorders, including chondromalacia, often are observed in this articulation. Chondromalacia via pathologic changes in cartilage may lead to qualitative impairment of knee joint motion. OBJECTIVE: To determine the patellofemoral joint motion quality in particular chondromalacia stages and to compare with controls. DESIGN: Retrospective, comparative study. SETTING: Voivodship hospitals, university biomechanical laboratory. PATIENTS: A total of 89 knees with chondromalacia (25 with stage I; 30 with stage II and 34 with stage III) from 50 patients and 64 control healthy knees (from 32 individuals). METHODS: Vibroacoustic signal pattern analysis of joint motion quality. MAIN OUTCOME MEASUREMENTS: For all knees vibroacoustic signals were recorded. Each obtained signal was described by variation of mean square, mean range (R4), and power spectral density for frequency of 50-250 Hz (P1) and 250-450 Hz (P2) parameters. RESULTS: Differences between healthy controls and all chondromalacic knees as well as chondromalacia patellae groups were observed as an increase of analyzed parameters (P < .001) with only one exception. No statistically significant difference between control group and stage I of chondromalacia patellae was found. All chondromalacia groups were differentiated by the use of all analyzed parameters (P < .01), whose values correspond to the progress of chondromalacia. CONCLUSIONS: Chondromalacia generates abnormal vibroacoustic signals, and there seems to be a relationship between the level of signal amplitude as well as frequency and cartilage destruction from the superficial layer to the subchondral bone. LEVEL OF EVIDENCE: IV.

Age-related impairment of quality of joint motion in vibroarthrographic signal analysis.

Aging is associated with degenerative changes in articular surfaces leading to quantitative and qualitative impairment of joint motion. Therefore, the aim of this study is to evaluate an age-related quality of the patellofemoral joint (PFJ) motion in the vibroarthrographic (VAG) signal analysis. Two hundred and twenty individuals were enrolled in this study and divided into five groups according to age. The VAG signals were collected during flexion/extension knee motion using an acceleration sensor and described using four parameters (VMS, P1, P2, and H). We observed that values of parameters VMS, P1, and P2 increase in accordance with the age, but H level decreases. The most significant differences were achieved between the youngest and the oldest participants' groups. Moreover, we show that parameters VMS, P1, and P2 positively correlate with age, contrary to negatively associated H parameter. Our results suggest that the impairment of joint motion is a result of age-related osteoarticular degenerative changes.