Local experience of laboratory activities in a BS physical therapy course: integrating sEMG and kinematics technology with active learning across six cohorts.

Introduction: Integrating technology and active learning methods into Laboratory activities would be a transformative educational experience to familiarize physical therapy (PT) students with STEM backgrounds and STEM-based new technologies. However, PT students struggle with technology and feel comfortable memorizing under expositive lectures. Thus, we described the difficulties, uncertainties, and advances observed by faculties on students and the perceptions about learning, satisfaction, and grades of students after implementing laboratory activities in a PT undergraduate course, which integrated surface-electromyography (sEMG) and kinematic technology combined with active learning methods. Methods: Six cohorts of PT students (n = 482) of a second-year PT course were included. The course had expositive lectures and seven laboratory activities. Students interpreted the evidence and addressed different motor control problems related to daily life movements. The difficulties, uncertainties, and advances observed by faculties on students, as well as the students' perceptions about learning, satisfaction with the course activities, and grades of students, were described. Results: The number of students indicating that the methodology was "always" or "almost always," promoting creative, analytical, or critical thinking was 70.5% [61.0-88.0%]. Satisfaction with the whole course was 97.0% [93.0-98.0%]. Laboratory grades were linearly associated to course grades with a regression coefficient of 0.53 and 0.43 R-squared (p < 0.001). Conclusion: Integrating sEMG and kinematics technology with active learning into laboratory activities enhances students' engagement and understanding of human movement. This approach holds promises to improve teaching-learning processes, which were observed consistently across the cohorts of students.

Effectiveness of virtual reality in relieving anxiety and controlling hemodynamics during oral surgery under local anesthesia: A prospective randomized comparative study.

It was the aim of the study to evaluate the contribution of a relaxing immersive experience with virtual reality (VR) goggles in reducing patient anxiety related to wisdom tooth extraction under local anesthesia. A prospective randomized comparative study in consecutive patients scheduled for bilateral wisdom tooth extraction under local anesthesia was carried out between March and December 2022. Both sides were operated upon in the same surgery, but on one side VR goggles were applied (VR), while on the other they were not (noVR). Anxiety was evaluated both subjectively (State-Trait Anxiety Inventory [STAI] and visual analogue scale [VAS]) and objectively (measuring heart rate, blood pressure [BP] and blood oxygen saturation) before (T1) and after each surgical step (T2VR and T2noVR). The study sample consisted of 27 patients: 9 men and 18 women, with an average age of 25.8 ± 6.5 years (range: 18-43). Anxiety as assessed by the STAI and VAS decreased from T1 to T2 (p < 0.001 and p < 0.001, respectively), although to a similar degree regardless of whether VR was used or not. Heart rate showed significant differences influenced by RV exposure (p = 0.013): it increased +2.5 ± 8.8 bpm in the control group and decreased -2.22 ± 7.55 bpm with VR (p = 0.013). Both minimum and maximum BP after surgery were significantly higher in the noVR group (p = 0.002 and p = 0.040, respectively). Regarding minimum BP, VR proved more effective among male patients (p = 0.057) and on starting the procedure using VR (p = 0.055). The results provided evidence of meaningful control of the hemodynamic variables, but less predictable performance in the subjective evaluation of anxiety.

Unique case study: Impact of single-session neuromuscular biofeedback on motor unit properties following 12 days of Achilles tendon surgical repair.

We explored the first evidence of a single-session neuromuscular biofeedback effect on motor unit properties, neuromuscular activation, and the Achilles tendon (AT) length 12 days after undergoing AT surgical repair. We hypothesized that immediate neuromuscular biofeedback enhances motor unit properties and activation without causing AT lengthening. After 12 days AT surgical repair, Medial Gastrocnemius (MG) motor unit decomposition was performed on a 58-year-old male before and after a neuromuscular biofeedback intervention (surface electromyography (sEMG) and ultrasonography), involving unressited plantar flexion. The analysis included motor unit population properties, sEMG amplitude, force paradigm, and AT length. There were increased MG motor unit recruitment, peak and average firing rate, coefficient of variation, and sEMG amplitude, and decreased recruitment and derecruitment threshold in the repaired AT limb. The non-injured limb increased the motor unit recruitment, and decreased the coefficient of variation, peak and average firing rate, inter-pulse interval, derecruitment threshold and sEMG amplitude. The AT length experienced -0.4 and 0.3 cm changes in the repaired AT and non-injured limb, respectively. This single-session neuromuscular biofeedback 12 days after AT surgery shows evidence of enhanced motor unit properties and activation without signs of AT lengthening when unresisted plantar flexion is performed in the repaired AT limb.

Multiclass Support Vector Machine improves the Pivot-shift grading from Gerdy's acceleration resultant prior to the acute Anterior Cruciate Ligament surgery.

INTRODUCTION: Rotatory laxity acceleration still lacks objective classification due to interval grading superposition, resulting in a biased pivot shift grading prior to the Anterior Cruciate Ligament (ACL) reconstruction. However, data analysis might help improve data grading in the operative room. Therefore, we described the improvement of the pivot-shift categorization in Gerdy's acceleration under anesthesia prior to ACL surgery using a support vector machine (SVM) classification, surgeon, and literature reference. METHODS: Seventy-five patients (aged 30.3 ± 10.2 years, and IKDC 52.0 ± 16.5 points) with acute ACL rupture under anesthesia prior to ACL surgery were analyzed. Patients were graded with pivot-shift sign glide (+), clunk (++), and (+++) gross by senior orthopedic surgeons. At the same time, the tri-axial tibial plateau acceleration was measured. Categorical data were statistically described, and the accelerometry and categorical data were associated (α = 5%). A multiclass SVM kernel with the best accuracy trained by orthopedic surgeons and assisted from literature for missing data was compared with experienced surgeons and literature interval grading. The cubic SVM classifier achieved the best grading. RESULTS: The intra-group proportions were different for each grading in the three compared strategies (p < 0.001). The inter-group proportions were different for all comparisons (p < 0.001). There were significant (p < 0.001) associations (Tau: 0.69, -0.28, and -0.50) between the surgeon and SVM, the surgeon and interval grading, and the interval and SVM, respectively. CONCLUSION: The multiclass SVM classifier improves the acceleration categorization of the (+), (++), and (+++) pivot shift sign prior to the ACL surgery in agreement with surgeon criteria.

Distal overactivation of gastrocnemius medialis in persistent plantarflexion weakness following Achilles tendon repair.

Structural alterations of the triceps surae and Achilles tendon (AT) can promote plantarflexion weakness one-year following an AT repair, influencing the activation strategies of the Gastrocnemius Medialis (GM) muscle. However, this is yet to be demonstrated. We aimed to determine whether patients with plantar flexion weakness one-year after AT repair show altered GM spatial activation. In this cross-sectional and case-control study, ten middle-aged men (age 34 ± 7 years old, and 12.9 ± 1.1 months post-surgery) with a high AT total rupture score who attended conventional physiotherapy for six months after surgery, and ten healthy control men (age 28 ± 9 years old), performed maximal and submaximal (40, 60 and 90%) voluntary isometric plantarflexion contractions on a dynamometer. The peak plantar flexor torque was determined by isokinetic dynamometry and the GM neuromuscular activation was measured with a linear surface-electromyography (EMG) array. Overall EMG activation (averaged channels) increased when the muscle contraction levels increased for both groups. EMG spatial analysis in AT repaired group showed an increased activation located distally at 85-99%, 75-97%, and 79-97% of the electrode array length for 40%, 60%, and 90% of the maximal voluntary isometric contractions, respectively. In conclusion, patients with persistent plantar flexion weakness after AT rupture showed higher distal overactivation in GM.

Occult metastases of oral maxillary squamous cell carcinoma: Systematic review and meta-analysis.

Squamous cell carcinoma (SCC) is the most common malignant neoplasm of the oral cavity. The performance of END (elective neck dissection) in cases of maxillary SCC is controversial because the literature traditionally classified maxillary tumors as having low metastatic potential. The aim of this systematic review and meta-analysis was to determine the percentage of occult cervical metastases in maxillary SCC to identify in which cases there is the need to perform an END. We searched the PubMed database to select articles dated from 2000 to 2020 that fulfilled our inclusion criteria; finally, we reviewed 27 manuscripts. We show that the overall cervical and occult metastases rate was 35% and 19%, respectively. For T1, the percentage of occult metastasis rate was 11%; for T2, it was 16%; for T3, it was 20%; and for T4, it was 32%. We suggest END (levels I-II-III) as treatment to T3/T4 cN0 patients.

Preseason multiple biomechanics testing and dimension reduction for injury risk surveillance in elite female soccer athletes: short-communication.

BACKGROUND: Injury risk is regularly assessed during the preseason in susceptible populations like female soccer players. However, multiple outcomes (high-dimensional dataset) derived from multiple testing may make pattern recognition difficult. Thus, dimension reduction and clustering may be useful for improving injury surveillance when results of multiple assessment tools are available. AIM: To determine the influence of dimension reduction for pattern recognition followed by clustering on multiple biomechanical injury markers in elite female soccer players during preseason. METHDOLOGY: We introduced the use of dimension reduction through linear principal component analysis (PCA), non-linear kernel principal component analysis (k-PCA), t-distributed stochastic neighbor embedding (t-sne), and uniform manifold approximation and projection (umap) for injury markers via grid search. Muscle strength, muscle function, jump technique and power, balance, muscle stiffness, exercise tolerance, and running performance were assessed in an elite female soccer team (n = 21) prior to the competitive season. RESULTS: As a result, umap facilitated the injury pattern recognition compared to PCA, k-PCA, and t-sne. One of the three patterns was related to a team subgroup with acceptable muscle conditions. In contrast, the other two patterns showed higher injury risk profiles. For our dataset, umap improved injury surveillance through multiple testing characteristics. CONCLUSION: Dimension reduction and clustering techniques present as useful strategies to analyze subgroups of female soccer players who have different risk profiles for injury.

Is the Rotatory Knee Stability Immediately Decreased Following a Competitive Soccer Match?

Fatigue induced by soccer playing increases physical efforts, which might alter the transverse knee stability, a known factor that promotes knee injuries, particularly anterior cruciate ligament injury. Thereby, primarily, we aimed to determine whether rotatory knee stability decreases immediately following a competitive soccer match in amateur players. Furthermore, we assessed the role of the preferred and non-preferred limbs to kick a ball in rotatory knee stability and the correlation between performance parameters and rotatory knee stability. We hypothesized that the knee stability decreases immediately after a competitive soccer match in amateur players. Eight healthy amateur soccer players (aged 27.2 ± 4.7 years and with body mass index of 23.8 ± 1.2 kg m-2) were included immediately before and after a competitive soccer match. The rotatory knee stability was assessed in the preferred and non-preferred limbs through the acceleration and jerk of the pivot shift maneuver and by the internal knee rotation of a pivoting landing task. Two-way repeated-measures ANOVA for factors time (before and after the soccer match) and limb (preferred and non-preferred) and multiple comparisons were performed using α = 5%. There was a statistical significance for the main factor time in the acceleration (5.04 vs. 6.90 ms-2, Δ = 1.86 ms-2, p = 0.020, η2 = 0.331) and jerk (18.46 vs. 32.10 ms-2, Δ = 13.64 ms-2, p = 0.004, η2 = 0.456) of the pivot shift maneuver. Rotatory stability decreases following a competitive soccer match in amateur soccer players under fatigue. Both the acceleration and jerk during the pivot shift maneuver is increased without significant internal knee rotation changes during the pivoting landing task.

Effects of Elbow Crutch Locomotion on Gluteus Medius Activation During Stair Ascending.

Crutches can help with the locomotion of people with walking disorders or functional limitations. However, little is known about hip muscle activation during stair ascending using different crutch locomotion patterns in people without disorders and limitations. Thus, we determined the acute effects of elbow crutch locomotion on gluteus medius (GM) activity during stair ascending. This comparative analytic cross-sectional study enrolled ten healthy men (22.0 ± 0.47 years). Participants climbed up the stairs with elbow crutches using one or two crutches, with ipsilateral or contralateral use, and after loading or unloading a limb. EMG signals were recorded from anterior, middle, and posterior portions of the GM and compared between the crutch conditions. The Kruskal-Wallis test and Dunn's multiple comparison test were performed (α = 5%). The activation of the GM increased with the ipsilateral use of crutches, with two crutches and three points, and when all the load depended only on one limb. GM activation decreased with contralateral use and in the unload limb. In conclusion, ascending stairs with elbow crutches alters the GM activation. The more critical factors were choosing the crutches' lateral use, the number of crutches, and if the limb is loaded or unloaded while ascending the stairs. Our findings can be helpful to increase or decrease the GM activation for those who use or will use crutches.

Steadiness training improves the quadriceps strength and self-reported outcomes in persistent quadriceps weakness following nine months of anterior cruciate ligament reconstruction and failed conventional physiotherapy.

Background Persistent quadriceps weakness may occur after anterior cruciate ligament reconstruction, limiting the strength gain. However, steadiness strengthening might change the inability to gain strength. Hence, we determined whether strength training with force steadiness and visual biofeedback can improve knee quadriceps torque, self-reported pain and knee stability in patients with persistent quadriceps weakness after knee anterior cruciate ligament reconstruction. Methods Twenty-five patients (aged 43.7 ± 12.2 years) with persistent quadriceps weakness following knee anterior cruciate ligament reconstruction and 34-weeks of physiotherapy performed unilateral strength training for both lower limbs. Four-weeks of conventional physiotherapy at week-30 were given, confirming the inability to gain torque. Then, steadiness training (isometric knee extension with visual biofeedback) was given for 7-weeks. Knee quadriceps peak torque, strength improvement, determination of responders to the intervention, coherence of strength gain between limbs, and self-reported outcomes (pain and knee stability) were obtained. Descriptive statistics and data inference using mixed-ANOVA, McNemar test, and χ2 test were described. Findings Quadriceps torque in the reconstructed knee improved (98.2 ± 47.2-155.2 ± 78.9 Nm; p = 0.031) for most patients (84%). Nevertheless, the torque was lower than the healthy side maintaining asymmetry (155.2 ± 78.9 vs. 209.5 ± 101.8 Nm; p = 0.026). There was high (20%) and medium coherence (80%) between limbs. Knee stability and pain improved in 72% of the patients (p < 0.001). Interpretations Steadiness training after anterior cruciate ligament reconstruction followed 9 months of surgery and failed conventional physiotherapy, improves the persistent weakness and self-reported outcomes, but gain strength was dissimilar between limbs.

A Balanced Arthroscopic Debridement of the Inner Layer of the Knee Retinaculum Increases the Tibiofemoral Joint Space Width.

INTRODUCTION: Traditional techniques can enlarge the medial tibiofemoral joint space width (JSW) for meniscal repairs, but a remnant ligament laxity may be developed. Alternatively, the debridement of the inner retinaculum layer may result in a balanced JSW without causing extra-ligament damage (retinaculum layers II and collateral ligament). PURPOSE: The purpose of this study was to determine whether a concentric arthroscopic debridement of the inner retinaculum layer increases the tibiofemoral JSW in patients with meniscal injuries. Secondarily, we determine whether the increase in JSW is symmetrical between compartments and describe the rate of complications and patient satisfaction. METHOD: Twenty middle-aged (15 male and five female) patients diagnosed with acute meniscal injury aged 36 ± 12 years were enrolled. The patients were submitted to an arthroscopic debridement of the inner layer of the knee retinaculum for both the medial and lateral compartments. The tibiofemoral JSW was measured intra-articularly using a custom instrument. A two-way ANOVA for repeated measures was used to compare the JSW. A Bland-Altman analysis and test-retest analysis were performed. RESULTS: The JSW increased following the debridement of the inner retinaculum layer, for both the medial and lateral compartments (p < 0.001). No complications were identified, and the patients were satisfied with the intervention. The minimal detectable change and bias of the custom instrument were 0.06 mm and 0.02 mm, respectively. CONCLUSION: The debridement allows a clinically important (>1 mm) symmetric tibiofemoral JSW enlargement. The technique suggests favoring the diagnosis of meniscus injuries and manipulating arthroscopic instruments without secondary complications after one year.

Pattern analysis of a complete Achilles tendon rupture suffered during high jump preparation in an official national-level athletic competition.

Elite athletes are subject to injuries like the Achilles tendon rupture. This injury requires a long recovery process, with no guarantee of returning to the pre-injury level. When a rupture happens during natural life, movement analysis can provide useful insights concerning patterns of rupture to understand and prevent Achilles tendon injuries. Here we determined the pattern of rupture of an Achilles tendon (AT) in an elite high-jumper athlete who ruptured an AT during the straight line running phase in preparation for a high-jump attempt. This study is a novel case report regarding a national-level elite athlete. The main outcomes were kinematics parameters obtained from video analysis. The pattern of the rupture was determined by pixel intensity and outlier analysis. The rupture occurred at 44% of the single stance. The injured leg showed a higher ankle dorsal flexion and knee-ankle ratio, and a lower knee flexion compared to contralateral leg. An eccentric pattern of rupture occurred during the transition from the mid to terminal stance phases of running. The lower knee flexion and the increased ankle dorsal flexion during the stance suggest a loss of knee-ankle coordination. This might have favoured a major elongation of Achilles tendon causing the rupture.

Do the heel-rise test and isometric strength improve after Achilles tendon repair using Dresden technique?

BACKGROUND: Achilles' tendon ruptures result in impaired plantar flexion strength and endurance. It is interesting to know the plantar flexion strength, the number of heel-rise repetitions, and the maximal calf circumference following Achilles' tendon ruptures repair. METHODS: Both the injured and non-injured legs of thirty male patients with Achilles' tendon ruptures treated with the percutaneous Dresden technique were compared with the ankle function of 30 healthy participants. Rehabilitation involved partial weight-bearing for three weeks and then increased to full weight-bearing and ankle exercises. RESULTS: The injured legs had weaker plantar flexion strength (1.64 ± 0.17 Nm/kg) compared with the non-injured legs (1.91 ± 0.24 Nm/kg; p = 0.002) and the healthy participants' legs (1.93 ± 0.32 Nm/kg; p < 0.001). The non-injured leg had greater ability in doing heel-rise repetitions (39.4 ± 6.1 rep.) compared with the injured legs (37.2 ± 5.7 rep.; p < 0.023) and the healthy participants' legs (31.0 ± 13.0 rep.; p < 0.001). CONCLUSIONS: The injured leg had not recovered full isometric strength but had improved heel-rise repetition.

Biased instantaneous regional muscle activation maps: Embedded fuzzy topology and image feature analysis.

The instantaneous spatial representation of electrical propagation produced by muscle contraction may introduce bias in surface electromyographical (sEMG) activation maps. Here, we described the effect of instantaneous spatial representation (sEMG segmentation) on embedded fuzzy topological polyhedrons and image features extracted from sEMG activation maps. We analyzed 73,008 topographic sEMG activation maps from seven healthy participants (age 21.4 ± 1.5 years and body mass 74.5 ± 8.5 kg) who performed submaximal isometric plantar flexions with 64 surface electrodes placed over the medial gastrocnemius muscle. Window lengths of 50, 100, 150, 250, 500, and 1,000 ms and overlap of 0, 25, 50, 75, and 90% to change sEMG map generation were tested in a factorial design (grid search). The Shannon entropy and volume of global embedded tri-dimensional geometries (polyhedron projections), and the Shannon entropy, location of the center (LoC), and image moments of maps were analyzed. The polyhedron volume increased when the overlap was <25% and >75%. Entropy decreased when the overlap was <25% and >75% and when the window length was <100 ms and >500 ms. The LoC in the x-axis, entropy, and the histogram moments of maps showed effects for overlap (p < 0.001), while the LoC in the y-axis and entropy showed effects for both overlap and window length (p < 0.001). In conclusion, the instantaneous sEMG maps are first affected by outer parameters of the overlap, followed by the length of the window. Thus, choosing the window length and overlap parameters can introduce bias in sEMG activation maps, resulting in distorted regional muscle activation.

Achilles Tendon Allograft Preparation Technique for Anterior Cruciate Ligament Reconstruction: A Technical Note.

Several factors associated with graft preparation for the surgery of the anterior cruciate ligament (ACL) like the wrong thawed, prophylaxis, bone cuts, excessive bone removal as well as positioning problems like a tunnels-graft mismatch, insufficient harvesting of the donor's tendon, size graft limitations (length and diameter), uncontrolled rotation of graft in their longitudinal axis, over or under tensioned graft, fixation mistakes, bone defects, secondary arthrofibrosis or morbidity of the donor site, and others factors importantly affect the outcomes of the ACL surgery. In this sense, the Achilles tendon Allograft is an advantageous technique where many of the previous limitation factors described can be controlled during an appropriate preparation. However, to obtain the maximum potentialities of the graft a detailed knowledge of the preparation is required. Hence, we aimed to describe how to prepare the Achilles tendon Allograft to control the graft's length and diameter, bone removal, and fixation requirements.

Intraoperative pivot-shift accelerometry combined with anesthesia improves the measure of rotatory knee instability in anterior cruciate ligament injury.

PURPOSE: The knee stiffness acquired following an Anterior Cruciate Ligament (ACL) injury might affect clinical knee tests, i.e., the pivot-shift maneuver. In contrast, the motor effects of spinal anesthesia could favor the identification of rotatory knee deficiencies prior to ACL reconstruction. Hence, we hypothesized that the intra-operative pivot-shift maneuver under spinal anesthesia generates more acceleration in the lateral tibial plateau of patients with an injured ACL than without. METHODS: Seventy patients with unilateral and acute ACL rupture (62 men and 8 women, IKDC of 55.1 ± 13.8 pts) were assessed using the pivot-shift maneuver before and after receiving spinal anesthesia. A triaxial accelerometer was attached to the skin between Gerdys' tubercle and the anterior tuberosity to measure the subluxation and reduction phases. Mixed ANOVA and multiple comparisons were performed considering the anesthesia and leg as factors (alpha = 5%). RESULTS: We found a higher acceleration in the injured leg measured under anesthesia compared to without anesthesia (5.12 ± 1.56 m.s- 2 vs. 2.73 ± 1.19 m.s- 2, p < 0.001), and compared to the non-injured leg (5.12 ± 1.56 m.s- 2 vs. 3.45 ± 1.35 m.s- 2, p < 0.001). There was a presence of significant interaction between leg and anesthesia conditions (p < 0.001). CONCLUSIONS: The pivot-shift maneuver performed under anesthesia identifies better rotatory instability than without anesthesia because testing the pivot-shift without anesthesia underestimates the rotatory subluxation of the knee by an increased knee stiffness. Thus, testing under anesthesia provides a unique opportunity to determine the rotational instability prior to ACL reconstruction.

Understanding the effect of window length and overlap for assessing sEMG in dynamic fatiguing contractions: A non-linear dimensionality reduction and clustering.

The Short-Time Fourier transform (STFT) is a helpful tool to identify muscle fatigue with clinical and sports applications. However, the choice of STFT parameters may affect the estimation of myoelectrical manifestations of fatigue. Here, we determine the effect of window length and overlap selections on the frequency slope and the coefficient of variation from EMG spectrum features in fatiguing contractions. We also determine whether STFT parameters affect the relationship between frequency slopes and task failure. Eighty-eight healthy adult men performed one-leg heel-rise until exhaustion. A factorial design with a window length of 50, 100, 250, 500, and 1000 ms with 0, 25, 50, 75, and 90% of overlap was used. The frequency slope was non-linearly fitted as a task failure function, followed by a dimensionality reduction and clustering analysis. The STFT parameters elicited five patterns. A small window length produced a higher slope frequency for the peak frequency (p < 0.001). The contrary was found for the mean and median frequency (p < 0.001). A larger window length elicited a higher slope frequency for the mean and peak frequencies. The largest frequency slope and dispersion was found for a window length of 50 ms without overlap using peak frequency. A combination of 250 ms with 50% of overlap reduced the dispersion both for peak, median, and mean frequency, but decreased the slope frequency. Therefore, the selection of STFT parameters during dynamic contractions should be accompanied by a mechanical measure of the task failure, and its parameters should be adjusted according to the experiment's requirements.

Tolerancia a la fatiga muscular isométrica de alta intensidad transcurrido un año de evolución de tenorrafias del tendón de Aquiles: resultados preliminares / Tolerance to high intensity isometric muscle fatigue after one year of evolution of Achilles tendon tenorrhaphies: preliminary results

Introducción: Desafortunadamente, posterior a una tenorrafia del tendón de Aquiles existe abandono de la práctica deportiva. Frente ello, son desconocidas las causas y si la capacidad de tolerancia a la fatiga muscular podría ser un factor en disfunción. Objetivo: Comparar la pendiente y tiempo de la fatiga isométrica de la musculatura plantiflexora superficial entre participantes con una tenorrafia del tendón de Aquiles posterior a 1 año y participantes sanos. Métodos: Diez hombres con tenorrafia Aquiliana y tratamiento kinésico convencional (36,7 ± 10,2 años, 172,6 ± 6,1 cm, 83,1 ± 10,9 kg, IMC 27,3 ± 2,8 kg/m2) y diez participantes sanos (29,9 ± 12,0 años, 171,8 ± 5,8 cm, 81,3 ± 12,0 peso corporal, IMC 27,5 ± 3,7 kg/m2) fueron incorporados. Los participantes realizaron una prueba plantiflexora isométrica en un dinamómetro mientras se registró una señal electromiográfica en gastrocnemio medial con un electrodo de alta densidad. La pendiente de la frecuencia peak y el tiempo hasta la fatiga fueron comprados con una prueba-t (α = 5%). Resultados: No se observaron diferencias de las pendientes entre ambos grupos (grupo sano, -0,0051 ± 0,0078 Hz/s vs grupo con tenorrafia, -0,0082 ± 0,0091 Hz/s; p = 0.513). No hubo diferencias para el tiempo hasta la fatiga entre los grupos (grupo sano, 36,1 ± 17,9 s vs grupo con tenorrafia, 32,8 ± 16,0 s; p = 0.692). Conclusión: La tolerancia a la fatiga muscular y el tiempo necesario para sostenerla en alta intensidad (90%) no es un factor de disfunción en pacientes con tenorrafia Aquiliana y terapia kinésica convencional con 1 año postquirúrgico.

Introduction: Unfortunately, after a tenorrhaphy of the Achilles tendon, there is an abandonment of sports practice. Both their causes are unknown, and if the ability to tolerate muscle fatigue may be in dysfunction. Objetive: Here, we compared the fatigue slope of the peak frequency and the time to isometric fatigue of plantar flexors between participants with an Achilles tendon tenorrhaphy after one year of evolution and healthy participants. Methods: Ten men with Achilles tenorrhaphy and traditional physical therapy (36.7 ± 10.2 years, 172.6 ± 6.1 cm, 83.1 ± 10.9 kg, BMI 27.3 ± 2.8 kg/m2) and ten healthy participants (29.9 ± 12.0 years, 171.8 ± 5.8 cm, 81.3 ± 12.0 kg, BMI 27.5 ± 3.7 kg/m2) were included. The participants performed an isometric contraction of plantar flexors on a dynamometer while high-density electromyography signals were recorded. The slope of peak frequency and time to fatigue were compared with a t-test (α = 5%). Results: For frequency slope there was not difference between groups (Healthy group = -0.0051 ± 0.0078 Hz/s vs Tenorrhaphy group = -0.0082 ± 0.0091 Hz/s; p = 0.513). For time to fatigue there was not difference between groups (Healthy group = 36.1 ± 17.9 s vs Tenorrhaphy group = 32.8 ± 16.0 s; p = 0.692). Conclusion: The tolerance to muscle isometric fatigue and the time to fatigue required to sustain it at a high intensity (90%) is not a factor of dysfunction in patients with Achilles tenorrhaphy treated with conventional physical therapy.

Video-based biomechanical analysis of an unexpected Achilles tendon rupture in an Olympic sprinter.

We used image-processing techniques to determine the moment (i.e., image frame) of the Achilles tendon (AT) rupture in an Olympic sprinter. This report may be unique due to the difficulty in conducting motion capture analyses during injury events. Our report includes one female Olympic sprinter, 29 years old (body mass: 56 kg, height: 1.68 m, and body mass index: 19.8 kg/m2) with a high-competitive profile history (2008 and 2012 Olympic Games participation; South American record holder in 100- and 200-m; Pan-American gold medalist in 200-m and 4 × 100-m relay) who suffered a complete AT rupture in the left leg while exercising in the final phase of rehabilitation following an Achilles tendinopathy in the contralateral limb. The greater dorsiflexion found at the moment of the injury and the delayed control of heel position indicated the presence of uncontrolled dorsiflexion, which potentially generated excessive eccentric stress over the tendon and, thus, the AT rupture. Here we discuss the relevance of lower leg alignment, the movements' characteristics, and the history of Achilles tendinopathy in the contralateral leg on the occurrence of the AT rupture.