Respiratory muscle strength and pulmonary function in unvaccinated athletes before and after COVID-19 infection: A prospective cohort study

PURPOSE

We investigated abnormalities and recovery in respiratory function after COVID-19 infection in an unvaccinated elite athlete population.

METHODS

Measurements included maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF).

RESULTS

The most frequent reported symptoms were fatigue with 80% and muscle/joint pain and headache with 50%, whereas only 10% reported dyspnoea and 30% cough. During follow-up, MIP was up to 13% and MEP up to 8% lower following COVID-19 infection. Likewise, FEV₁ was up to 2% and FVC up to 5% lower. While MEP and FEV₁ rapidly normalised, MIP and FVC still remained abnormal after 52 days of COVID-19 infection, thereby leading to a restrictive ventilatory pattern. PEF seemed unaffected during follow-up.

CONCLUSIONS

COVID-19 decreases respiratory function in unvaccinated athletes despite reporting few respiratory symptoms and having mild disease. An initiative aimed at reducing the long-term adverse effects following COVID-19 infection seems warranted, which perhaps may be avoided through vaccination.

Post-Operative Results of ACL Reconstruction Techniques on Single-Leg Hop Tests in Athletes: Hamstring Autograft vs. Hamstring Grafts Fixed Using Adjustable Cortical Suspension in Both the Femur and Tibia

Background and Objectives: Anterior cruciate ligament (ACL) tears are common injuries in the athletic population, and accordingly, ACL reconstruction (ACLR) is among the most common orthopedic surgical procedures performed in sports medicine. This study aims to compare the semitendinosus/gracilis (ST/G) and ACL hamstring grafts fixed using adjustable cortical suspension in both the femur and tibia (MAI) ACLR techniques. We aimed to compare the results of single-leg hop tests (SLHT) applied in different directions and limb symmetry indices (LSI) in athletes with a 6-month post-operative ACLR history. Materials and Methods: A retrospective cohort of 39 athletes from various sports branches who underwent MAI (n = 16) and ST/G (n = 23) ACLR techniques by the same surgeon were evaluated. The knee strength of the participants on the operated and non-operated sides was evaluated with five different SLHTs. The SLHT included the single hop for distance (SH), triple hop for distance (TH), crossover triple hop for distance (CH), medial side triple hop for distance (MSTH), and medial rotation (90°) hop for distance (MRH). Results: There was a significant improvement in the mean Lysholm, Tegner, and IKDC scores in the post-operative leg for both techniques (p < 0.05) compared to the pre-operative levels. When there was a difference between the SH of the operative and the non-operative legs in the ST/G technique (p < 0.05), there was no significant difference in the other hop distance for both ST/G and MAI (p > 0.05). There was no difference between the techniques regarding the LSI scores. Conclusions: The fact that our research revealed similar LSI rates of the SLHTs applied in different directions in the ST/G and MAI techniques assumes that the MAI technique can be an ACLR technique which can be functionally used in athletes.

A comparative study of the acute effects of knee brace vs. kinesiotape on selected isokinetic strength variables of the knee muscles

BACKGROUND: Different methods of treatment for preventing knee injuries, enhancing knee strength and minimising post-injury risks have been explored. Among these methods, Kinesio tape (KT) and knee braces (KB) are commonly used. OBJECTIVE : To investigate the acute effects of KT and KB on isokinetic knee strength parameters. METHODS: A total of 15 healthy sedentary male subjects voluntarily participated in the study. Concentric isokinetic knee extension (EX) and flexion (FLX) strength were measured at three sessions: 1. Baseline 2. with KT (’KT’) 3. with KB (’KB’). Tests were performed at 60, 180 and 240∘/s. Peak moment (PM), Hamstring/Quadriceps ratio (HQR), and joint angle at peak moment (JAPM) were measured. RESULTS: ‘KT’ and ‘KB’ were associated with increase in PMEX, PMFLX, HQR at 60 and 240∘/s (p< 0.05) and increased JAPMEX. No significant difference was observed at 180∘/s (p> 0.05). CONCLUSION: In healthy individuals, ‘I’ shape KT and KB positively affect EX and FLX strengths and HQR, especially at low angular velocity.

EFFECT OF AN EIGHT-WEEK CORE STRENGTH TRAINING ON SOME PERFORMANCE PARAMETERS IN FOOTBALL REFEREES

The aim of this study was to examine the effects of eight-week core strength training (CST) in addition to specific trainings of football referees on sprint, agility and anaerobic power. Forty nine male football referees participated in the study. The subjects were divided into two groups as experimental group (EG, n = 24) and control group (CG, n = 25). An eightweek CST program was implemented in the EG. The CG subjects participated in their respective sport training routine. 10m., 20m sprint, pro-agility, vertical jump (VJ) and long jump (LJ) were measured both before (pre-test) and after (post-test) the eight weeks. Anaerobic power (AP) was calculated using Lewis formula. Paired samples ttest was used for statistical analyses. There were significant improvements in 10m, 20m, VJ and AP between pre-test and post-test of EG (p>0.05). There were significant improvements only in 20m. sprint for CG between pre-test and post-test (p<0.05 ). It was found that the eight-week CST in addition to specific trainings of football referees had positive effects on their 10m., 20m. sprint and VJ jump. However, it was thought that this effect was not directly associated with CST and that this development occurred since referees already had an intense training program based on speed and anaerobic power. This thought was supported with literature. Core stabilization tests performed before and after CST to football referees in future studies will give positive results in terms of increasing the reliability of results.

INFLUENCE OF CORE STRENGTH TRAINING ON PEAK MUSCLE TORQUE OF QUADRICEPS AND HAMSTRING IN YOUNG SOCCER PLAYERS

The purpose of the present study was to investigate the effect of eight week core strength training (CST) on quadriceps and hamstring muscle strength and H/Q ratio. The study included a total of 20 young soccer players, 10 in the experimental group (EG) and 10 in the control group (CG). Isokinetic knee strength measurements at angular velocities of 60°sec−1 , 180°sec−1 and 240°sec−1 were performed on the subjects. Independent sample t-test and 2x2 ANOVA test were used for statistical analysis. No significance was found between the pre-test results of both EG and CG (p>0.05). In post-test results, a difference was found in favour of EG group in RPM 60o EX value (p<0.05). When the pre-test and posttest results of the groups were compared separately, a significant difference was found in RPM 60o EX, LPM 180o EX and LPM 240o EX parameters in EG (p<0.05). A significant progress was found in LPM 180o EX, LPM 180o FLX and LPM 240o FLX values in CG (p<0.05). It was found that CST applied on young soccer players affected knee isokinetic strength in different velocity and this effect caused significance especially in different angular speeds of EX phase. In addition, although significant progress was not observed in all parameters in EG after CST, it was found that there weren’t decreases in any parameters and at least strength was maintained.

Electromyographic responses of knee isokinetic and single-leg hop tests in athletes :dominant vs. non-dominant sides

The purpose of the study is to perform the electromyographic (EMG) analysis of isokinetic and single-leg hop tests (SLHTs). We included 20 healthy male athletes (age: 23.18 years, height: 178.82 cm, weight: 73.76 kg and BMI: 47 kg/m²) voluntarily. Isokinetic knee strength tests at at 60°sec^-1, 180°sec^-1, 240°sec^-1 velocities and different SLHTs; Single leg (SL), Triple leg (THD) and Crossover (CHD) hop for distance tests, 6 m timed-hop test (6 m THT), Single leg vertical jump test (VJ) were measured. Muscle activations of quadriceps (Q); vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF) and hamstring (H); biceps femoris (BF) were obtained. There were significant differences in SL, THD, CHD and VJ in DS (p < 0.05).VJ revealed a statistical significance in NDS (p = 0.003). The comparison of the activations produced by the same muscles in different tests showed statistically significant differences in all the muscles for both sides (p < 0.05). In conclusion, we determined that the muscles produce similar activations in the isokinetic tests for both the DS and NDS, whereas there are differences in some of the SLHTs. The most active muscles were VM and RF (medial muscles) in isokinetic tests, and VL (lateral muscle) in SLHTs.g.

Inspiratory muscle training improves pulmonary functions and respiratory muscle strength in healthy male smokers

The aim of the present study is to investigate the effects of inspiratory muscle training (IMT) on pulmonary function and respiratory muscle strength of both healthy smokers and nonsmokers. Forty-two healthy males (16 in the IMT smokers group [IMT_S], 16 in the IMT nonsmokers group [IMT_N], and 10 in the placebo group) participated in the present study. Using a randomized, double-blind, placebo-controlled design, IMT_S and IMT_N underwent 4 weeks of 30 breaths twice daily at 50% (+5% increase each week) of maximum inspiratory pressure (MIP), while the placebo group maintained 30 breaths twice daily at 15% MIP using an IMT device. The data were analyzed with repeated measures for one-way analysis of variance, 3 × 2 mixed factor analysis of variance, and least significant difference tests. Respiratory muscle strength (MIP and maximal expiratory pressure [MEP]) and pulmonary functions significantly improved after a 4-week period (between the pre and posttests) in the IMT_N and IMT_S groups (p < 0.05). The mean difference and percentage differences showed significant alterations in the respiratory muscle strength, forced and slow pulmonary capacities, and pulmonary volume between the IMT_N and IMT_S groups (p < 0.05). There were significant changes in the expiratory muscle strength (MEP), slow vital capacity (SVC), and forced pulmonary measurements (forced expiratory volume after 1 s and maximal voluntary ventilation) between IMT_N and IMT_S groups in favor of smokers (p < 0.05). These results show that greater improvements occurred in smokers after IMT. Increased respiratory muscle strength may be the underlying mechanism responsible for this improvement. Additionally, the benefits of IMT were greater in smokers than nonsmokers. This difference between smokers and nonsmokers may potentially be explained by higher influence of exercise on smokers' lung microbiome, resulting in greater reversal of negative effects.