UNASSIGNED: Beausejour, JP, Guinto, G, Artrip, C, Corvalan, A, Mesa, MF, Lebron, MA, and Stock, MS. Successful powerlifting in a unilateral, transtibial amputee: A descriptive case series. J Strength Cond Res 38(5): e243-e252, 2024-There are no reports in the literature of powerlifting success after amputation. We had the unique opportunity to characterize functional outcomes, strength, muscle contractility and size, and corticospinal excitability in an accomplished, competitive powerlifter (best competition squat = 205.0 kg, deadlift = 262.7 kg) with a unilateral, transtibial amputation relative to amputee controls. Four men (age range = 23-49 years) with unilateral, lower-limb amputation (3 transtibial, 1 transfemoral) participated in 1 laboratory visit. We assessed 10-m gait speed, the timed up and go (TUG) test, 5-time sit-to-stand performance (5TSTS), contractile properties of the vastus lateralis (VL) and medial gastrocnemius by tensiomyography, and VL cross-sectional area (CSA) by ultrasonography. Unilateral assessments for the intact limb included isokinetic knee extension and flexion torque and power and transcranial magnetic stimulation derived corticospinal excitability. An interview with the powerlifter provided contextual perspective. Compared with the control subjects, the powerlifter performed the 5TSTS faster (6.8%), exhibited faster VL contraction times (intact limb = 12.2%; residual limb = 23.9%), and showed larger VL CSA for the intact limb (46.7%). The powerlifter exhibited greater knee extension and flexion peak torque and mean power, particularly at 180°·s -1 , as well as greater corticospinal excitability for the intact VL (65.6%) and tibialis anterior (79.6%). By contrast, the control subjects were faster in the TUG (18.3%) and comfortable (13.0%) and fast (21.4%) in the 10-m walk test. The major themes of our interview included needing to modify lifting mechanics, persistence, and remarkable pain tolerance. Our findings highlight the impressive neuromuscular adaptations that are attainable after lower-limb amputation.

OBJECTIVE: Involuntary pelvic floor muscle (PFM) contractions are thought to occur during an increase in intra-abdominal pressure (IAP). Although no studies have assessed their presence in women with normal pelvic floor (PF) function, existing literature links the absence of involuntary PFM contractions to various PF dysfunctions. This study rectifies this lacuna by evaluating involuntary PFM contractions during IAP in healthy nulliparous women with no PF dysfunction, using visual observation and vaginal palpation. Results were compared with the literature and the IUGA/ICS Terminology Reports.
METHODS: Nulliparous (n=149) women performed three sets of three maximal coughs. Visual observation and vaginal palpation were conducted in the standing and supine positions. The women were not instructed to contract their PFMs. Occurrence rates were calculated for each assessment method and position; differences between positions were analyzed using the Chi-squared test.
RESULTS: Rates of occurrence of involuntary PFM contraction were low across both assessments and positions (5-17%). Significant differences were found between standing (5%) and supine (15%) positions for visual observation, but not vaginal palpation (15%, 17% respectively). Occurrence rates also differed compared with the literature and terminology reports.
CONCLUSIONS: Contrary to clinical expectations, rates of occurrence of involuntary PFM contraction among our cohort of nulliparous women were extremely low. Digital palpation results showed high agreement with the terminology reports, but only partial agreement was observed for the visual observation results. Our study underscores the need for more research aimed at defining normal involuntary PF functions, a review of our understanding of involuntary PFM contractions, and better standardized guidelines for involuntary PFM assessment methods.

Recent systematic reviews and meta-analyses show that individuals with chronic neck pain (CNP) have altered respiratory muscle strength and abnormal respiratory mechanics. However, no study has investigated the diaphragmatic function in individuals with CNP compared to asymptomatic peers.
This study aimed to compare the respiratory muscle strength and diaphragmatic function between patients with CNP and asymptomatic controls.
Observational, case-control study.
A total of 25 women with CNP and 23 asymptomatic controls participated in this case-control study. The visual analog scale and neck disability index were used to assess the pain and disability characteristics of the CNP group. Maximum inspiratory and expiratory pressures (MIP and MEP) were measured to determine respiratory muscle strengths. The diaphragmatic function (muscle thickness in deep inspiration, Tins; and at the end of calm expiration, Texp; muscle thickness change, ΔT; contraction ratio, CR) were evaluated by two-dimensional ultrasonography.
The MIP (p = 0.001, d = 1.11), ΔT (p = 0.033, d = 0.63), and CR (p = 0.012, d = 0.75) of the diaphragm were found significantly reduced in the CNP group compared to asymptomatic controls whilst MEP, Tins, and Texp of the diaphragm were similar between study groups (p > 0.05). The intensity of neck pain was moderately correlated with MIP (r = -0.48), Tins (r = -0.46), and ΔT (r = -0.42) while NDI (r = -0.42) had a moderate correlation with Tins (p < 0.05).
The present findings revealed that women with CNP have altered diaphragmatic function. Thus, screening and targeting diaphragm may improve the rehabilitation process in CNP. However, further experimental studies regarding the efficacy of breathing exercise approaches are needed.

Adults with late-onset Pompe disease (aLOPD) are characterized by muscular contractile tissue deterioration. However, their neuromuscular performances are poorly known. We aimed to compare maximal muscle strength, activation, explosive strength and neuromuscular fatigue between aLOPD and controls. We studied 20 aLOPD and 20 matched controls. Isometric maximum voluntary contraction (MVC) torque was obtained for the hip, knee and ankle muscles. The voluntary activation level (VAL) during knee extensor MVC was assessed using interpolated twitch technique. Explosive strength was evaluated for knee and ankle muscles through the rate of torque development (RTD) during fast contractions. Neuromuscular fatigue was measured during a 30-second contraction of knee flexors and extensors. All muscle MVC torques were significantly lower in aLOPD than controls (p <0.05). The weakest muscles were the hip extensors followed by hip abductors and abductors. Raw value of RTD was lower in aLOPD for the majority of muscles (p <0.05). No intergroup differences were reported for normalized RTD, VAL and neuromuscular fatigue (p-values> 0.05). Our study shows that maximal strength was the only neuromuscular characteristic affected in aLOPD with a proximal-distal intensity gradient. This suggests that the surviving muscle tissue of aLOPD is as functionally efficient as that of control individuals.

Non-specific low back pain represents 90-95% of all cases of low back pain and it has a prevalence of 18% in the adult population, assuming a great socioeconomic impact. The main objective of this observational case-control study study is to evaluate if there are differences in the simultaneous contraction of the core muscles between nonspecific low back pain and healthy subjects. This study will be carried out in the Physiotherapy department of the University of Alcalá. Eighty-two participants <18 years old, will be recruited, paired with NSLBP (n = 41) and healthy (n = 41). The main outcome will be the onset muscle contraction of lateral abdominal wall (internal oblique, external oblique and transversus abdominis), pelvic floor, lumbar multifidus and respiratory diafragm. The maneuvers that the subjects will perform will be abdominal drawing in maneouver, contralateral arm lift, valsalva, and voluntary pelvic floor contraction in sitting and standing. As a secondary objective, to analyze the amount of contraction of each muscle group and the capacity of the diaphragms to be excreted in both groups of subjects. Finally, to relate pain and disability.

OBJECTIVE: Postpartum lumbopelvic pain (PLPP) is common among women. Abdominal, diaphragm, and pelvic floor muscles (PFMs) modulate intraabdominal pressure as a part of the force closure mechanism. These muscles are exposed to changes during pregnancy that compromise the force closure mechanism. It was hypothesized that abdominal and PFMs activity, the direction of bladder base displacement, diaphragm thickness, and excursion might differ between women with and without PLPP during respiratory and postural tasks.
METHODS: Thirty women with and 30 women without PLPP participated in this case-control study. Ultrasound imaging was used to assess the abdominal, diaphragm, and PFMs during rest, active straight leg raising (ASLR) with and without a pelvic belt, and deep respiration.
RESULTS: The bladder base descent was significantly greater in the PLPP group than in the controls during deep respiration and ASLR without a belt (p = 0.026; Chi-squared = 6.40). No significant differences were observed between the groups in the abdominal muscles activity and diaphragm muscle thickness. There was a significant interaction effect of the group and the task for diaphragm excursion (F (2, 116) = 6.08; p = 0.00) and PFM activity (F (2, 116) = 5.22; p = 0.00). In the PLPP group, wearing a belt compromised altered PFM activation and direction of bladder base displacement.
CONCLUSIONS: The PFM activity, direction of bladder base displacement, and diaphragm excursion differed between groups during postural and respiratory tasks. Therefore, it is recommended to involve retraining of the PFMs and diaphragm muscle in the rehabilitation of women with PLPP.

The large body of published literature has shown that the effects of strength training can transfer from trained to untrained homologous limb muscles after unilateral training. These effects on strength have been shown to be very specific to the type and speed of training contraction. The aim of this study was to investigate the effects of a 4-week unilateral slow and fast velocity isokinetic concentric training, to compare the effects, and thus investigate whether these effects are speed-specific. Forty-four healthy female students allocated to slow training, fast training, or control performed 12 isokinetic concentric-concentric plantar/dorsal flexors training sessions (3 × 4 weeks) using their nondominant leg. Participants in the two experimental groups showed statistically significant gains in strength in both the trained (ranging from 8 to 41%) and untrained leg (5-26%), thus showing cross-education on strength effects. The present study demonstrated that 4 weeks (12 training sessions) of unilateral isokinetic resistance training in the concentric mode improved the strength of contralateral, untrained homologous muscles to the same extent, regardless of the contraction velocity used in females. Furthermore, the amount of concentric overload (50% more than during 60°/s) did not appear to affect the increase in strength gains. Therefore, practitioners are encouraged to use both training speeds when strength gains in the contralateral leg are the primary goal. If the training time is limited, however, training with a higher contraction speed is recommended.

The aim of this study is to investigate the differences in muscle contractile properties measured by the TMG method between top-level football players of different playing positions. The sample consisted of 57 football players from the Serbian Super League, divided into three groups: defenders-DF, midfielders-MF, and forwards-FW. Muscles included in the study were the Rectus Femoris (RF), Vastus Medialis (VM), Vastus Lateralis (VL), Biceps Femoris (BF), and Semitendinosus (ST) of the right (R) and left (L) leg. The TMG parameters used in this study were contraction time (Tc), delay time (Td), relaxation time (Tr), maximal displacement (Dm), and sustain time (Ts). The ANOVA results showed that differences in TMG parameters between top-level football players of different playing positions are small and exist only in the Tr of RF (F = 4.658, p = 0.014), BF (F = 4.433, p = 0.016), and ST muscle (F = 3.808, p = 0.028), and the Tc (F = 3.214, p = 0.048) and Td (F = 3.705, p = 0.031) of the VM muscle. All differences were detected between DF and FW players, and all differences were in the left (non-dominant) leg. The results obtained in this study indicate that the training and selection process in football, from the aspect of functional and mechanical muscle properties, should be similar for all players, regardless of playing position. It has been shown that TMG has relatively low sensitive strength for detecting differences between football players of different playing positions.

The aim was to assess and report the effects of menstrual cup on pelvic floor muscles (PFM) function and tone, as well as check the acceptability after a period of three menstrual cycles in healthy young women. The data collected in assessments and reassessments included the International Consultation on Incontinence Questionnaire - Vaginal Symptoms (ICIQ-VS) questionnaire, evaluation of PFM function through PERFECT Scheme, PFM muscle tone, and PFM manometry (Peritron 9300®). A diary regarding the overall colletor acceptability and satisfaction was collected. Ten healthy young women completed the study. There was an improvement in the mean values of maximal voluntary contraction (MVC) (p = 0.032), a decrease in the vaginal resting pressure (VRP) (p = 0.05), and an increase in the number of repetitions of sustained muscle contractions (p = 0.042). Seven women reported some discomfort while using the vaginal cup only in the first cycle while three revealed discomfort during the whole experiment. This study provides preliminary case-based evidence that the use of the vaginal cup for a period of three menstrual cycles changes the VRP, MVC, and PFM tone, as well as improves the repetitions of PFM assessed by digital palpation. Moreover, the women reported the use of vaginal cup as a positive experience.

It is important to understand the effects of rapid changes in weight on neuromuscular functions of combat athletes. The purpose of this case study was to investigate time-course changes in muscle strength, muscle size, and neural input during rapid weight loss in a professional boxer. One professional male boxer (26 yr) participated in two matches during measurements: welterweight (66.6 kg; weight loss: WL) and super welterweight (69.85 kg; control: CON). His muscle contraction properties and body composition were measured from 6 wk (baseline) before the matches to 1 wk after them. Maximal voluntary isometric knee extension torque, muscle cross-sectional area (mCSA) of the vastus lateralis using ultrasound, and high-density surface electromyography of the vastus lateralis during submaximal ramp-up contraction were measured. Individual motor units were identified, and modified discharge rates were calculated from a regression line between the recruitment threshold and discharge rates at 60%-70% of maximum torque according to the baseline value. His body weights for WL and CON decreased from 70.80 and 71.42 kg at the baseline to 68.75 and 71.36 kg immediately before the matches, respectively. Muscle strength changed little for either match. For WL, skeletal muscle mass and mCSA decreased, but there was no decrease for CON. The modified motor unit discharge rate for WL increased immediately before the match compared with other periods but did not change for CON. After rapid weight loss, neural input increased to compensate for lost muscle mass, and muscle strength was maintained.NEW & NOTEWORTHY This case study found that neural input to muscle, which was evaluated by high-density surface electrocardiography, increased to compensate for the decline of body weight and muscle mass and to maintain muscle strength during rapid weight loss, while neuromuscular characteristics were not markedly changed during no significant weight loss.