In this article, we aimed to describe what happens in skeletal muscle after dry needling intervention using magnetic resonance imaging (to show if there is edema) and tensiomyography (to measure contractile properties). At the same time, we describe the relationship between pain, edema, and contractility. Our results suggest that in asymptomatic patients, the application of dry needling over latent trigger points produce intra-muscular edema, an increase in muscle stiffness and an improved muscle contraction time.

(1) Background: Myofascial pain syndrome (MPS) is a clinical condition characterized by localized non-inflammatory musculoskeletal pain caused by myofascial trigger points. Diathermy or Tecar therapy (TT) is a form of noninvasive electro-thermal therapy classified as deep thermotherapy based on the application of electric currents. This technique is characterized by immediate effects, and its being used by high performance athletes. (2) Methods: A total of thirty-two participants were included in the study who were professional basketball players. There was a 15-person Control Group and a 17-person Intervention Group. TT was applied in the Intervention Group, while TT with the device switched off (SHAM) was applied in the Control Group. The effects were evaluated through the Lunge test, infrared thermography, and pressure threshold algometry at baseline, 15, and 30 min after the intervention. (3) Results: the Intervention Group exhibited a greater increase in absolute temperature (F_[1,62] = 4.60, p = 0.040, η²_p = 0.13) compared to the Control Group. There were no differences between the groups in the Lunge Test (F_[1.68,53.64] = 2.91, p = 0.072, η²_p = 0.08) or in pressure algometry (visual analog scale, VAS) (F_[3.90] = 0.73, p = 0.539, η²_p = 0.02). No significant short-term significant differences were found in the rest of the variables. (4) Conclusions: Diathermy can induce changes in the absolute temperature of the medial gastrocnemius muscle.

The aim was to determine the effects of changing pulse duration and electrode size on muscle contractile properties. Thirty-six healthy young male participated in the study (age 24.8 ± 5.8 years; height 178.2 ± 0.6 cm; body mass 71.8 ± 7.3 kg; self-reported weekly moderate intensity activity 3.5 ± 1.2 h·week⁻¹). Tensiomyography was used to assess rectus femoris (RF) and vastus medialis (VM) muscles neuromuscular properties of the dominant leg according to the electrode size (3.2–5 cm) and the stimulus length (0.2, 0.5, and 1 ms). Maximal radial displacement (Dm); Contraction time (Tc); Delay time (Td); Sustained time (Ts) and Half relaxation time (Tr) were measured. Relative and absolute reliability was quantified. To analyze the effects of the electrode and the stimulus length, a repeated-measures analysis of variance was used. Dm and Tc parameters showed for both muscles an excellent relative (0.95–0.99) and absolute reliability (1.6–4.2%). However, Ts and Tr showed low values of absolute reliability (4.4–40.9%). The duration of the stimulus length applied to the RF and VM and electrode size significantly influences muscle’s contractile properties (p < 0.05; η²_p = 0.09–0.60). The Dm increases substantially as the duration of the stimulus increases and with the use of the larger electrode in both muscles. However, Tc and Td are less affected by both conditions and not entirely clear. Practically, our study suggests that a stimulus pulse duration of 1 ms together with a 5 × 5 cm electrode is necessary to reach a reliable and reproducible assessment of both RF and VM muscles contractile properties.

Objective: Trigger points (TrPs) are hypersensitive spots within taut bands of skeletal muscles that elicit referred pain and motor changes. Among the variety of techniques used for treating TrPs, dry needling is one of the most commonly applied interventions. The question of eliciting local twitch responses (LTRs) during TrP dry needling is unclear. Our main aim was to investigate the evolution of the electromyographic (EMG) peak activity of each LTR elicited during dry needling into latent TrPs of the gastrocnemius medialis muscle. Methods: Twenty asymptomatic subjects with latent TrPs in the gastrocnemius medialis muscle participated in this cross-sectional study. Changes in EMG signal amplitude (root mean square [RMS]) with superficial EMG were assessed five minutes before, during, and five minutes after dry needling. The peak RMS score of each LTR was calculated (every 0.5 sec). Results: Analysis of variance revealed a significant effect (F = 29.069, P <0.001) showing a significant decrease of RMS peak amplitude after each subsequent LTR. Differences were significant (P <0.001) during the first three LTRs, and stable until the end of the procedure. No changes (P =0.958) were found for mean RMS data at rest before (mean = 65.2 mv, 95% confidence interval [CI] = 47.3–83.1) and after (61.0 mv, 95% CI = 42.3–79.7) dry needling. Conclusions: We found that, in a series of LTRs elicited during the application of dry needling over latent TrPs in the medial gastrocnemius muscle, the RMS peak amplitude of each subsequent LTR decreased as compared with the initial RMS peak amplitude of previous LTRs. No changes in superficial EMG activity at rest were observed after dry needling of latent TrPs of the gastrocnemius medialis muscle.

Background: Understanding the hip adduction and abduction strength in female soccer players is crucial for performance enhancement and injury prevention. This study compares the strength profiles in these muscle groups between elite and sub-elite female soccer players and assesses the impact of leg limb-dominance. Methods: A descriptive-comparative study was employed. Eighty-two female soccer players were evaluated. Isometric hip-adduction and abduction strength were measured using a handheld dynamometer. Results: Female elite and sub-elite soccer players displayed a mean and standard deviation (SD) on isometric hip-adductor strength for dominant (3.19 Nm/kg ± 0.69 vs. 2.40 Nm/kg ± 0.67) and non-dominant leg (3.32 Nm/kg ± 0.76 versus 2.42 Nm/kg ± 0.70), respectively. For isometric hip-abductor strength in elite and sub-elite players, a mean and SD of dominant (2.86 Nm/kg ± 0.56 vs. 2.07 Nm/kg ± 0.50) and non-dominant (2.80 Nm/kg ± 0.59 vs. 2.04 Nm/kg ± 0.43). In essence, elite players were stronger than sub-elite players on isometric hip-adduction (mean difference [MD] = 0.82 Nm/kg, CI_95% = 0.42–1.12) and abduction (MD = 0.83 Nm/kg, CI_95% = 0.54- 1.12) both in dominant and non-dominant, leg, whereas no differences existed for hip adduction:abduction ratios between groups and legs. Conclusions: Elite female athletes exhibited greater strength than sub-elite female players in both hip adduction and abduction, whereas adduction:abduction ratio values did not differ between the two groups or between different legs.