Does an Adjusted Kinematic Model Predict the Relative Eccentric Force During Nordic Curl?

This study aimed to assess the combination of video-based kinematic variables adjusted by intrinsic covariates to predict the relative eccentric force (RelF) during the Nordic curl. The participants (n = 21) performed Nordic curls (3 trials; 3-min rest) on a device measuring the eccentric force. The peaks were normalized by body weight. Kinovea software was used to track angular and linear velocity and acceleration from recorded videos. Two prediction models with multiple linear regression equations associated kinematic, anthropometric, and age variables to adjust the actual RelF. The equations obtained the predicted RelF. The actual RelF was inversely correlated with height (r = -.52), tangential (r = -.50) and centripetal accelerations (r = -.715), and angular velocity (r = -.70). The best prediction models combined angular velocity with age (F2,18 = 15.1, P = .001, r = .792, r2 = .627) and with height (F2,18 = 14.5, P = .001, r = .785, r2 = .616). No differences were observed between actual and predicted values (P = .993-.994), with good levels of agreement and consistency (intraclass correlation coefficient = .77-.78; Cronbach α = .86-.87). Bland-Altman results showed high levels of agreement and low biases. The standard error of measurement and minimal detectable change ranges were 0.46 to 0.49 N/kg and 1.28 to 1.36 N/kg, respectively. Also, the percentage of standard error of measurement was below 10% (7.92%-8.35%). The coefficient of variation analysis returned a 14.54% and 15.13% for each model, respectively. Kinematic analysis offers portability and low cost to current expensive or technical impaired dynamometry-based techniques to assess the RelF.

Acute Effects of Single- Versus Double-Leg Postactivation Potentiation on Postural Balance of Older Women: An Age-Matched Controlled Study.

AIMS: To compare the postactivation potentiation effects of isometric contraction until failure in double- and single-leg tasks on older women's balance. METHODS: The one-legged balance test was performed before and immediately after a rise-to-toes task until the task failure. Older women were divided into two groups: a group performed the task with double leg (n = 43) and the other group with single-leg support (n = 55). RESULTS: The single-leg group showed slower velocity of sway post rise-to-toes task (pre = 4.02 ± 1; post = 3.78 ± 1.15 m/s; p = .04) without differences for the center of pressure path length (pre = 79 ± 21; post = 75 ± 23 cm; p = .08). In the double-leg group, faster velocity of sway (pre = 4 ± 1.22; post = 4.25 ± 1.13; p = .03) and increased center of pressure path length (pre = 80 ± 24; post = 85 ± 23 cm; p = .03) were observed after the task. CONCLUSIONS: The single-leg group showed improved balance outcomes due to postactivation potentiation, while the double-leg group showed worsened balance consistent with muscle fatigue.

Effects of 4-Week Diacutaneous Fibrolysis on Myalgia, Mouth Opening, and Level of Functional Severity in Women With Temporomandibular Disorders: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to assess the effects of 4-week protocol of diacutaneous fibrolysis (DF) compared with simulated DF (sham-DF) on myalgia and mouth opening. METHODS: In a sham randomized controlled trial, 34 women with temporomandibular disorders and myofascial pain were randomly divided as intervention group (IG) and sham-DF group (SG). The IG received 4 weeks of real DF, and the SG received sham. Pain was assessed through the visual analog scale and pressure pain thresholds (PPTs) on the temporomandibular joint (TMJ), and over the temporal and masseter muscles. The Mandibular Function Impairment Questionnaire was used to classify the participants regarding to the severity of the functional limitation related to TMD. RESULTS: Pain scores decreased for both groups, but the IG showed lower values at week 4, with between-group differences. Bilateral temporal PPT showed higher values at week 4, with between-group differences. The SG had lower PPTs but the IG had higher PPTs, both compared to baseline results. The time-by-group interaction and the frequency of participants above 40 mm of mouth opening showed a significant difference for the IG over time with higher results at the 4-week assessment compared to its own baseline. Both groups showed lower MFIQ scores from baseline to 4-week assessment. There was a lower frequency of a moderate level of severity for the IG. No differences were observed for TMJ or for the masseter muscles PPT. CONCLUSION: Improvements were observed for visual analog scale scores and PPTs on temporal muscles. There was a group-by-time interaction in the IG, suggesting a possible potential use of DF for mouth opening.

Changes on Walking During Street Crossing Situations and on Dorsiflexion Strength of Older Caribbean Americans After an Exercise Program: A Pilot Study.

The objective of this pilot study was to evaluate a 6-month exercise program completed by 10 older Caribbean Americans. Assessments were done at baseline and 3 and 6 months, and included walks on an instrumented mat at preferred speed, and during street crossing simulations with regular (10 s) and reduced time (5 s). There were no significant differences on preferred walking speed over time. Differences between the street crossing conditions were found only at 6 months. Significant changes over time among the assessments were found only during street crossing with reduced time. Street crossing with reduced time was the only walking condition sensitive to capture changes associated with participating in the exercise program. There was a significant increase in dorsiflexion strength overtime. At 6 months it was significantly higher than at baseline and 3 months. The program was feasible, acceptable, and had some positive effects on walking, knee flexion, and dorsiflexion strength.

Activity of Lower Limb Muscles During Squat With and Without Abdominal Drawing-in and Pilates Breathing.

Barbosa, AC, Martins, FM, Silva, AF, Coelho, AC, Intelangelo, L, and Vieira, ER. Activity of lower limb muscles during squat with and without abdominal drawing-in and Pilates breathing. J Strength Cond Res 31(11): 3018-3023, 2017-The purpose of this study was to assess the effects of abdominal drawing-in and Pilates breathing on the activity of lower limb muscles during squats. Adults (n = 13, 22 ± 3 years old) with some Pilates experience performed three 60° squats under each of the following conditions in a random order: (I) normal breathing, (II) drawing-in maneuver with normal breathing, and (III) drawing-in maneuver with Pilates breathing. Peak-normalized surface electromyography of the rectus femoris, biceps femoris, gastrocnemius medialis, and tibialis anterior during the knee flexion and extension phases of squat exercises was analyzed. There were significant differences among the conditions during the knee flexion phase for the rectus femoris (p = 0.001), biceps femoris (p = 0.038), and tibialis anterior (p = 0.001), with increasing activation from conditions I to III. For the gastrocnemius medialis, there were significant differences among the conditions during the knee extension phase (p = 0.023), with increased activity under condition I. The rectus and biceps femoris activity was higher during the extension vs. flexion phase under conditions I and II. The tibialis anterior activity was higher during the flexion compared with the extension phase under all conditions, and the medial gastrocnemius activity was higher during the extension phase under condition I. Doing squats with abdominal drawing-in and Pilates breathing resulted in increased rectus, biceps femoris, and tibialis anterior activity during the flexion phase, increasing movement stability during squat exercises.

No Evidence of Short-term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients.

OBJECTIVE: The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain (USP) patients. METHODS: A randomized, double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with USP were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold, glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately, and 72 hours after the intervention in the infraspinatus and deltoid muscles. RESULTS: A single application of real dry needling resulted in lower pain intensity scores and a larger range in glenohumeral internal rotation 72 hours after the intervention in comparison with sham dry needling. No differences in pressure pain threshold or muscle activity were observed due to the intervention. DISCUSSION: A single application of real dry needling resulted in clinically significant changes in the short term. No differences were detected in muscle activation in the infraspinatus or deltoid muscles. Complementary interventions and longer follow-up times may be required to observe changes in muscle activity.

Does 8-Week Resistance Training with Slow Movement Cadenced by Pilates Breathing Affect Muscle Strength and Balance of Older Adults? An Age-Matched Controlled Trial.

This study investigated the balance and dorsiflexion strength of older adults after eight weeks of resistance training, with the exercise velocity cadenced by the Pilates breathing technique and the volume modulated by the session duration. Forty-four older adults were divided into two groups: resistance training (TR; n = 22) and resistance training with the Pilates breathing technique cadencing all exercises (TR + P; n = 22), both during eight weeks. The total exercising volume was controlled by time of execution (50 min/session). The dorsiflexion strength and balance were assessed. The RT group showed higher dorsiflexion strength after the protocol: Right (RT = 29.1 ± 7.7 vs. RT + P = 22.9 ± 5.2, p = 0.001) and Left (RT = 29.5 ± 6.9 vs. RT + P = 24.0 ± 5.2, p = 0.001). All balance parameters were improved in RT + P group compared to its own baseline: Path Length (cm) (pre = 71.0 ± 14.3 vs. post = 59.7 ± 14.3, p = 0.003); Sway Velocity (cm/s) (pre = 3.6 ± 0.7; post = 2.9 ± 0.7; p = 0.001); Sway Area (cm2) (pre = 8.9 ± 5.3 vs. post = 5.7 ± 2.1, p = 0.003); Excursion Medio Lateral (cm) (pre = 3.0 ± 0.7 vs. post = 2.6 ± 0.5 cm, p = 0.002); and Excursion AP (cm) (pre = 3.6 ± 1.4 vs. post = 2.8 ± 0.7 cm, p = 0.010). Resistance training using slower velocity movement cadenced by Pilates breathing technique produced balance improvements compared to baseline (moderate to large effect sizes), but no between-group effect was observed at the end of the protocol. The dorsiflexion strength was higher in the RT group compared to RT + P group.

Eight-week equipment-based Pilates exercises positively affects quality of life, and functional capacity in non-active adult women: a randomized controlled trial.

BACKGROUND: The Pilates exercises are popular for muscle conditioning among women. However, the effects on conditioning of healthy non-active adult women due to Pilates practicing are not fully explained. The aim of this randomized controlled trial was to assess the effects of equipment-based Pilates exercises on the percentage of body fat, weight, body mass index (BMI), functional capacity, and quality of life of adult healthy women. METHODS: Seventy-eight non-active women were randomly assigned to 2 groups (Pilates or Control). The Pilates group performed a total of 16 exercise sessions (60 minutes each, performed twice a week for 8 consecutive weeks). The control group was instructed to perform no exercise. Percentage of body fat (DXA scans), weight, BMI, distance covered in the incremental shuttle walk test, maximal oxygen uptake (VO2max), and quality of life (SF-36 scores) were analyzed. RESULTS: There were no significant between-group differences at baseline, but significant group-by-time interaction was observed for Pilates group postintervention. Higher distance covered (P=0.01), VO2max (P=0.04), and quality of life (P=0.04) were observed after the intervention compared to the control group. No differences were observed for body composition. CONCLUSIONS: Two months of equipment-based Pilates training improved functional capacity and quality of life in healthy adult women.

Balance and Gait of Frail, Pre-Frail, and Robust Older Hispanics.

Older Hispanics are an understudied minority group in the US, and further understanding of the association between frailty, gait and balance impairments in disadvantaged older Hispanics is needed. The objectives of this study were to compare the balance and gait of older Hispanics by their frailty status. Sixty-three older Hispanics (21 men, 42 women, mean age 75 ± 7 years) attending senior centers in disadvantaged neighborhoods were grouped by their frailty status and completed balance and walking tests at a preferred speed and during street crossing simulations. Sixteen percent (n = 10) of the participants were frail, 71% (n = 45) were pre-frail, and 13% (n = 8) were robust. Frail participants had poorer balance than robust participants (F = 3.5, p = 0.042). The preferred walking speed of frail and pre-frail participants was lower (F = 6.3, p < 0.011) and they took shorter steps (F > 3.5, p = 0.002) than robust participants. During street crossing conditions, frail participants had wider steps (F = 3.3, p = 0.040), while pre-frail participants walked slower (F = 3.6, p = 0.032), and both took shorter steps than robust participants (F > 3.5, p < 0.043). Frailty and pre-frailty were prevalent and associated with gait and balance impairments in disadvantaged older Hispanics. The findings can inform the development of programs and interventions targeting this vulnerable underserved population.