Isometric Hip Research Articles

Functional Hip Characteristics and Their Relationship With Ball Velocity in College Baseball Pitchers.

Compared to shoulder and elbow functions, the hip functional characteristics of baseball pitchers have not been fully investigated. Therefore, little is known about the relationship between hip function and pitching performance. The purpose of this study was to evaluate the characteristics of hip flexibility and strength, focusing on their influences on the ball velocity in baseball pitchers. Descriptive laboratory study. Laboratory and university baseball facility. Twenty-three college baseball pitchers. Passive hip range of motion (ROM) and isometric hip muscle strength were bilaterally measured. The pitchers threw 20 fastballs at an official pitching distance. Bilateral hip ROM and strength in flexion, extension, abduction, adduction, and external and internal rotation; the maximal ball velocity. The pivot side showed smaller hip external rotation ROM (P < .01), larger hip internal rotation ROM (P = .03), and greater hip adduction strength (P = .03) than the stride side. The hip extension ROM on the stride side had a negative correlation with the maximal ball velocity (r = -.58, P < .01). The maximal ball velocity (135.3 [4.1]km/h) positively correlated with the hip extension (r = .59, P < .01), flexion (r = .57, P < .01), abduction (r = .55, P < .01), and adduction (r = .55, P < .01) strength on the pivot leg, and the hip flexion (r = .53, P = .01), abduction (r = .67, P < .01), and adduction (r = .46, P = .03) strength on the stride leg. These findings suggest that baseball pitchers do not have marked side-to-side differences in hip flexibility and strength, and that an important fitness factor for increasing ball velocity is not the hip flexibility but the hip muscle strength of both legs.

Association of Functional Screening Tests and Noncontact Injuries in Division I Women Student-Athletes.

Warren, M, Lininger, M, Smith, CA, Copp, A, and Chimera, NJ. Association of functional screening tests and noncontact injuries in Division I women student-athletes. J Strength Cond Res 34(8): 2302-2311, 2020-To determine the association between functional screening tests and lower-body, noncontact injuries in Division I women basketball, soccer, and volleyball student-athletes (SA). Sixty-eight injury-free women SA (age: 19.1 ± 1.1 years, height: 171.3 ± 8.7 cm, and mass: 68.4 ± 9.5 kg) were tested preseason with single hop (SH), triple hop (TH), and crossover hop (XH) for distance, and isometric hip strength (abduction, extension, and external rotation) in randomized order. The first lower-body (spine and lower extremity), noncontact injury requiring intervention by the athletic trainer was abstracted from the electronic medical record. Receiver operating characteristic and area under the curve (AUC) were calculated to determine cut-points for each hopping test from the absolute value of between-limb difference. Body mass-adjusted strength was categorized into tertiles. Logistic regression determined the odds of injury with each functional screening test using the hopping tests cut-points and strength categories, adjusting for previous injury. Fifty-two SA were injured during the sport season. The cut-point for SH was 4 cm (sensitivity = 0.77, specificity = 0.43, and AUC = 0.53), and for TH and XH was 12 cm (sensitivity = 0.75 and 0.67, specificity = 0.71 and 0.57, AUC = 0.59 and 0.41, respectively). A statistically significant association with TH and injuries (adjusted odds ratio = 6.50 [95% confidence interval: 1.69-25.04]) was found. No significant overall association was found with SH or XH, nor with the strength tests. Using a clinically relevant injury definition, the TH showed the strongest predictive ability for noncontact injuries. This hopping test may be a clinically useful tool to help identify increased risk of injury in women SA participating in high-risk sports.

FMS Corrective Intervention Improves FMS Composite Score and 1-Mile Run Time, without Concurrent Change in Hip Extension Strength, Vertical Jump or T-Shuttle Run Time, in Recreational Runners

The purpose of this research was to examine the effect of an intervention designed to improve functional movement as determined by Functional Movement Screen ™ (FMS) composite scores, one mile run time, standing isometric hip extension strength, agility T-Test time, and vertical jump in recreational runners (N=12, 7 males and 5 females; Mean Age = 49.08±15.87 yrs.; and mean weekly run volume = 15.96±21.21 miles), while normal running training load was maintained. We employed a two group (Control and Treatment) randomized experimental design. The treatment group (n=6) completed a 6 week intervention using the standard corrective methodology advocated by the FMS organization in combination with their normal run training, while the control group (n=6) continued their normal run training without additional intervention. We found a significant interaction between group and pre/post measure with a large effect sizes demonstrating improvement in the treatment group for the both the 1 mile run time (F = 5.45, p=0.042, Ɲp2= 0.353) and the FMS composite score (F = 10.55, p=0.009, Ɲp2= 0.513). There were no other significant interactions or meaningful effect sizes for any other dependent variable. This study supports the concept that a 6 week standard FMS intervention can result in concurrent improvements in both FMS composite score and 1 mile running performance without a concurrent change in running training load, isometric hip extension strength, vertical jump performance or t-shuttle times, in recreational runners.

Reliability of maximum isometric hip and knee torque measurements in children with cerebral palsy using a paediatric exoskeleton – Lokomat

The Lokomat (by L-Force tool) allows the measurement of the maximum voluntary isometric torque (MVIT) at the knee and hip joints in a standing position, as close as possible to the posture adopted during walking. However, the reliability of this measurement in children with cerebral palsy (CP) remains unknown. The main goal of this study was to evaluate inter and intra-tester reliability of a novel tool (L-Force) in CP population. L-Force reliability was determined in 17 children with CP by two experienced therapists. We collected MVITs in hip and knee flexors and extensors. Relative and absolute reliability of maximum joint torques were estimated using the intra-class correlation coefficient (ICC) and standard error of measurement (SEM), respectively. The correlation between L-Force and hand-held dynamometer (HHD) was also reported. ICCs were good to excellent for intra and inter-tester reliability (all P≤0.001). The SEM ranged from 2.0 to 4.1 Nm (12.1 to 21.7%) within-tester and from 2.1 to 3.5 Nm (11.9 to 22.5%) between testers. The correlation was fair to good between L-Force and HHD measures (r=[0.50-0.75]; all P˂0.01) with higher values for flexors than extensors. The L-Force is a reliable tool for quantifying the hip and knee flexors and extensors torques in children with cerebral palsy with an important timesaving and in a more functional posture than traditional HHD.

Clinically measured hip muscle capacity deficits in people with patellofemoral pain

ObjectiveTo evaluate differences in clinical measures of hip abductor and extensor capacity (strength, endurance and power) in people with patellofemoral pain (PFP) compared to asymptomatic controls. DesignCross-sectional. SettingsLaboratory. ParticipantsThirty-two physically active people (16 with PFP and 16 controls). Main outcome measuresStrength was evaluated isometrically using a hand-held dynamometer and dynamically using 10 repetitions maximum (10RM) tests. Power was assessed using a linear position transducer. Endurance was assessed using maximum number of repetitions. ResultsThe PFP group had significant deficits compared to the control group in isometric strength (21–25%) for hip abduction (ES = 0.98) and extension (ES = 0.85); in 10RM (15–18%) for hip abduction (ES = 0.72) and extension (ES = 0.85); and in power (24–31%) for hip abduction (ES = 0.80), and extension (ES = 0.94). No difference was identified for hip abduction and extension in endurance tests. ConclusionClinical assessments can identify deficits in isometric and dynamic hip strength, as well as power in people with PFP. Hip muscle capacity deficits in people with PFP including strength and power highlight a potential need for more progressive resistance training in this population.

Isometric hip strength and strength ratios in elite adolescent and senior Australian Rules Football players: an initial exploration using fixed-point dynamometry.

Introduction: First year Australian Football League (AFL) players have been found to be at higher risk of injury than established elite level players. While risk factors for sporting injuries are complex, muscle strength imbalances or deficits around the hip have been identified as a modifiable risk factors for lower limb (LL) injury. The objective of this study was to investigate hip strength and hip strength ratios in un-injured Australian Football (AF) players, spanning from late adolescence into early adulthood.

Low-Load Resistance Training With Blood Flow Restriction Improves Clinical Outcomes in Musculoskeletal Rehabilitation: A Single-Blind Randomized Controlled Trial.

Background: There is growing evidence to support the use of low-load blood flow restriction (LL-BFR) exercise in musculoskeletal rehabilitation.Purpose: The purpose of this study was to evaluate the efficacy and feasibility of low-load blood flow restricted (LL-BFR) training versus conventional high mechanical load resistance training (RT) on the clinical outcomes of patient’s undergoing inpatient multidisciplinary team (MDT) rehabilitation.Study design: A single-blind randomized controlled study.Methods: Twenty-eight lower-limb injured adults completed a 3-week intensive MDT rehabilitation program. Participants were randomly allocated into a conventional RT (3-days/week) or twice-daily LL-BFR training group. Outcome measurements were taken at baseline and 3-weeks and included quadriceps and total thigh muscle cross-sectional area (CSA) and volume, muscle strength [five repetition maximum (RM) leg press and knee extension test, isometric hip extension], pain and physical function measures (Y-balance test, multistage locomotion test—MSLT).Results: A two-way repeated measures analysis of variance revealed no significant differences between groups for any outcome measure post-intervention (p > 0.05). Both groups showed significant improvements in mean scores for muscle CSA/volume, 5-RM leg press, and 5-RM knee extension (p < 0.01) after treatment. LL-BFR group participants also demonstrated significant improvements in MSLT and Y-balance scores (p < 0.01). The Pain scores during training reduced significantly over time in the LL-BFR group (p = 0.024), with no adverse events reported during the study.Conclusion: Comparable improvements in muscle strength and hypertrophy were shown in LL-BFR and conventional training groups following in-patient rehabilitation. The LL-BFR group also achieved significant improvements in functional capacity. LL-BFR training is a rehabilitation tool that has the potential to induce positive adaptations in the absence of high mechanical loads and therefore could be considered a treatment option for patients suffering significant functional deficits for whom conventional loaded RT is contraindicated.Trial Registration: ISRCTN Reference: ISRCTN63585315, dated 25 April 2017.

Lower Extremity Strength and Range of Motion in High School Cross-Country Runners.

Cross-country running is becoming an increasingly popular sport, with a significant participation noted at the high school level. The aim of this study was to compare gender and bilateral hip extension range of motion and hip and knee extension strength of high school cross-country runners. 31 participants volunteered from a local high school cross-country team (16 males and 15 females). The modified Thomas test was utilized to measure hip extension range of motion bilaterally using a digital inclinometer. In order to measure hip and knee isometric strengths, an isokinetic dynamometer was employed. A mixed model approach revealed a statistically significant difference in peak hip extension strength between genders but not the side. Male athletes demonstrated a 29.2 Nm/kg (P < 0.05) greater force production than females during isometric hip extension strength testing. There were no significant differences in peak knee extension isometric strength, hip extension range of motion, and the ratio of peak hip and knee strength between genders and the dominant and nondominant leg. Female cross-country runners should focus on increasing hip extension strength to help maintain hip stability during running. This may be beneficial in decreasing the chances of experiencing patellofemoral pain in long-distance runners.

Different neuromuscular parameters influence dynamic balance in male and female football players.

To analyse the relationship between several parameters of neuromuscular performance with unilateral dynamic balance measured through the Y-Balance test, as well as to determine the possible sex-related differences. The Y-Balance test, isokinetic (concentric and eccentric) knee flexion and extension strength, isometric hip abduction and adduction strength, lower extremity joint range of motion (ROM) (hip, knee and ankle) and core stability were assessed in male (n = 88) and female (n = 44) professional football players. A stepwise multivariate linear least square regression with backward elimination analysis was carried out to identify a group of factors that were independently associated with balance performance in both sexes. Passive hip flexion and ankle dorsiflexion with knee flexed ROM were the main factors that retained a significant association to dominant (R2 = 23.1) and non-dominant (R2 = 33.5) balance scores for males. For females, core stability, hip abduction isometric peak torque, passive hip abduction and ankle dorsiflexion with knee flexed ROM variables retained a significant association with balance scores for both, dominant (R2 = 38.2) and non-dominant (R2 = 46.9) legs. Training interventions aimed at improving or maintaining unilateral dynamic balance in male football players should include, among other things, stretching exercises for the posterior chain of the lower extremity. However, females should also include exercises for strength and mobility of the hip abductors and core stability (especially in the frontal plane). This knowledge would allow clinicians and sport practitioners to develop more effective and tailored unilateral dynamic balance training interventions in male and female football players, possibly improving performance and reducing the risk of injury. III.

Association between knee-to-hip flexion ratio during single-leg vertical landings, and strength and range of motion in professional soccer players

The aim of this study was to test the correlation between knee-to-hip flexion ratio during a single leg landing task and hip and knee strength, and ankle range of motion. Twenty-four male participants from a professional soccer team performed a continuous single leg jump-landing test during 10s, while lower limb kinematics data were collected using a motion analysis system. After biomechanical testing, maximal isometric hip (abduction, extension, external rotation), knee extension and flexion strength were measured. Maximum ankle dorsiflexion range of motion was assessed statically using the weight bearing lunge test. Pearson correlation coefficients were calculated to determine the associations between the predictor variables (knee and hip strength, and ankle ROM) and the main outcome measure (knee-to-hip flexion ratio). Correlation between knee-to-hip flexion ratio and hip abductors strength was significant (r = −0.47; p = 0.019). No other significant correlations were observed among the variables (p > 0.05). These results demonstrated that a lower hip abductors strength in male soccer players was correlated with a high knee-to-hip flexion ratio during landing from a single leg jump, potentially increasing knee overload by decreasing energy absorption at the hip. The results provide a novel proposal for the functioning of hip muscles to control knee overload.

Isometric Hip Strength and Dynamic Stability of Individuals With Chronic Ankle Instability.

Compared with individuals who have a history of lateral ankle sprain (LAS) without markers of chronic ankle instability (CAI; LAS copers) and healthy people, those with CAI often exhibit neuromuscular impairments and dynamic-stability deficits at the hip. However, the influence of hip-strength deficits on dynamic stability remains unknown. To compare isometric hip strength and dynamic stability in individuals with or without CAI and examine the degree of dynamic-stability variance explained by isometric hip strength. Case-control study. Research laboratory. Sixty individuals (47 women, 13 men; age = 23.7 ± 4.6 years, height = 166.6 ± 7.7 cm, mass = 70.8 ± 15.7 kg) separated into CAI, LAS coper, and control groups based on previously established criteria. Group differences in resultant vector time to stabilization (RVTTS) and isometric hip-extension, -abduction, and external-rotation strength were determined using 1-way analyses of covariance that controlled for sex and limb (dominant or nondominant) tested and Cohen d effect sizes (95% confidence intervals). Backward linear regressions and Cohen f2 effect sizes (95% confidence intervals) determined the amount of RVTTS variance explained by isometric hip strength. Significance was set a priori at P < .05. The CAI group had less isometric hip-extension strength than LAS copers ( P = .02, d = 0.72 [0.06, 1.34]) and controls ( P = .01, d = 1.19 [0.50, 1.84]) and less external-rotation strength than LAS copers ( P = .03, d = 0.78 [0.13, 1.41]) and controls ( P = .01, d = 1.02 [0.34, 1.65]). No group differences existed for RVTTS ( F2,57 = 1.16, P = .32) or abduction strength ( F2,57 = 2.84, P = .07). Resultant vector time to stabilization was explained by isometric hip strength for LAS copers ( R2 = 0.21, f2 = 0.27 [0.22, 0.32], P = .04) but not for the CAI ( R2 = 0.12, f2 = 0.14 [0.06, 0.22], P = .22) or control ( R2 = 0.10, f2 = 0.11 [0.03, 0.19], P = .18) groups. Participants with CAI had decreased isometric hip strength, but that did not equate to dynamic-stability deficits. Clinicians should include hip-muscle strengthening in rehabilitation protocols for patients with CAI, yet these gains may not enhance dynamic stability when landing from a jump.

Incidence and risk factors for back pain in young floorball and basketball players: A Prospective study.

The aim of this study was to investigate the incidence of back pain in young basketball and floorball players under 21years of age. The secondary aim was to examine risk factors especially for low back pain (LBP). Nine basketball and nine floorball teams (n=396) participated in this prospective follow-up study (2011-2014). Young athletes (mean age 15.8±1.9) performed physical tests and completed a questionnaire at baseline. The follow-up lasted 1-3years per player. During the follow-up, back pain reported by the players was registered on a weekly basis and verified by a study physician. The exposure time (AE) on team practices and games was recorded by the coach. Altogether back pain was reported 61 times by 51 players. The incidence of back pain was 87 per 1000 athlete-years and 0.4 per 1000hours of AE. Hamstrings, quadriceps and iliopsoas extensibility and general joint hypermobility were not associated with LBP. Furthermore, no association between LBP and leg extension strength or isometric hip abduction strength asymmetry was found in these young basketball and floorball players. In conclusion, back pain can lead to a considerable time-loss from training and competition among young basketball and floorball players and the pain tends to reoccur. Lower extremity muscle extensibility, general joint hypermobility or investigated lower extremity strength measures were not associated with the risk of LBP.

Changes in lower extremity function and pitching performance with increasing numbers of pitches in baseball pitchers.

Compared to upper extremity function, the changes in lower extremity function with increasing numbers of pitches have not fully been investigated in baseball pitchers. In addition, little is known about the correlation between lower extremity function and pitching performance. The purpose of this study was to evaluate the effect of fatigue on lower extremity function and pitching performance in a simulated baseball game. Eighteen collegiate baseball pitchers threw 117 pitches in 9 innings (13 pitches per inning) with 5-min rest between innings at an official pitching distance in a simulated game. Isometric hip muscle strength (abduction and adduction) and squat jump performance (height, mean/peak power, and mean/peak velocity) were measured before and after the game. The mean ball velocity and pitching accuracy were assessed per inning. Ball velocity significantly decreased in the 7th (P=0.026) and 9th (P=0.001) innings compared to the 1st inning, but pitching accuracy did not change significantly. Hip abduction (P=0.009) and adduction (P=0.001) strength significantly decreased after the game, but squat jump performance did not significantly change before and after the game. A significant correlation between decreased ball velocity in the 9th inning and decreased hip adduction strength was found (P=0.011, r=0.583). Our findings suggest that hip abduction and adduction strength are susceptible to fatigue owing to repetitive throwing motions and that hip adduction strength, especially, is an important physical fitness factor for maintaining ball velocity during a game in baseball pitchers.

Association Of Isometric Hip And Ankle Strength With Frontal Plane Kinetics In Females During Running

Association Of Isometric Hip And Ankle Strength With Frontal Plane Kinetics In Females During Running

Exercise therapy, patient education, and patellar taping in the treatment of adolescents with patellofemoral pain: a prospective pilot study with 6\xa0months follow-up

BackgroundPatellofemoral pain (PFP) is the most common knee condition among adolescents, with a prevalence of 6–7% resulting in reduced function and quality of life. Exercise therapy is recommended for treating PFP, but has only been tested in older adolescents (15–19 years). This pilot study aimed to investigate the adherence to, and clinical effects of, exercise and patient education in young adolescents (12–16 years), with PFP.MethodsTwenty adolescents (16 females) with PFP were recruited from a population-based cohort to undergo a 3-month multimodal intervention. This comprised of a 30-min patient education and group-based exercise therapy. Exercises included supervised lower extremity strength exercises three times per week, in addition to similar home-based strength exercises. Outcomes included a 7-point global rating of change scale (ranging from “completely recovered” to “worse than ever”), the Knee injury and Osteoarthritis Outcome Score (KOOS), physical activity scale (PAS), weekly sports participation and health-related quality of life measured by European Quality of Life 5 dimensions Youth (EQ-5DY) and isometric knee and hip muscle strength. Pain was measured on a visual analogue scale (VAS), and satisfaction treatment was measured on a five-point Likert scale ranging from “highly satisfied” to “not satisfied at all”. These were collected at 3- and 6-month follow-ups. Adherence to supervised exercise was measured as session attendance, and adolescent self-reported adherence to home-based exercises.ResultsAdherence to the exercise therapy was poor, with adolescents participating in a median of 16 (IQR 5.5–25) out of 39 possible supervised training session. Five out of 18 adolescents had a successful outcome after both 3 and 6 months. There were no relevant changes in isometric muscle strength.ConclusionThis was the first study to investigate adherence to, and clinical effects of, exercise therapy and patient education in young adolescents with patellofemoral pain. Adherence to the exercise therapy was low with little to no clinical effects making a full clinical trial impractical. Future studies need to explore how an intervention can be successfully tailored to young adolescents with patellofemoral pain to obtain good adherence while improving pain and function.

Knee flexion not hip extension strength is persistently reduced following hamstring strain injury in Australian Football athletes: Implications for Periodic Health Examinations

ObjectivesDetermine whether clinically feasible tests of isometric lower limb strength and range of motion (ROM) in Australian Football (AF) athletes are useful in Periodic Health Examinations to identify persistent deficits following hamstring strain injury (HSI). DesignCase-control. MethodsThirty-seven male, semi-professional AF athletes (mean±SD; age, 20.2±2.9years; height, 1.7±0.5m; mass, 81±9.2kg) participated, ten athletes (37%) reported HSI within the previous three seasons of competition. Comparisons of pre-season isometric knee flexion and hip extension strength variables (peak force, torque and torque normalised to body mass) and hip, knee and ankle ROM measures were made between athletes with and without past-history of HSI using linear mixed-effect models. A logistic regression evaluated whether any of the outcome measures could differentiate athletes with a past-history of HSI. ResultsKnee flexion peak force, torque and torque normalised to body mass were significantly reduced in athletes with a past-history of HSI (coefficient, 95% CI) (−44.8N, −86.3 to −3.3), (−22.2Nm, −40.5 to −3.7) and (−0.2Nmkg−1, −0.4 to 0.0) respectively. Knee flexion peak torque normalised to body mass (Nmkg−1) approached significance as a test was able to differentiate athletes with history of HSI (p=0.068). There were no differences between groups for any hip extension strength or lower limb ROM outcome measures. ConclusionsDeficits in isometric peak knee flexion strength persist for up to three seasons following HSI in AF athletes. Isometric knee flexion strength testing may be a clinically feasible option for Periodic Health Examinations and inform tertiary injury prevention strategies.

腹臥位、背臥位、prone standingの測定肢位において、ハンドヘルドダイナモメーターを用いて等尺性股関節伸展筋力を測定した時の検者内信頼性

腹臥位、背臥位、prone standingの測定肢位において、ハンドヘルドダイナモメーターを用いて等尺性股関節伸展筋力を測定した時の検者内信頼性

Physical Performance Measures of Flexibility, Hip Strength, Lower Limb Power, and Trunk Endurance in Healthy Navy Cadets: Normative Data and Differences Between Sex and Limb Dominance.

Lopes, TJA, Simic, M, Alves, DdS, Bunn, PdS, Rodrigues, AI, Terra, BdS, Lima, MdS, Ribeiro, FM, Vilão, P, and Pappas, E. Physical performance measures of flexibility, hip strength, lower limb power, and trunk endurance in healthy navy cadets: Normative data and differences between sex and limb dominance. J Strength Cond Res 35(2): 458-464, 2021-The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single-leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a 2-way mixed analysis of variance. A total of 545 Brazilian Navy cadets (394 men) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean ± SD, 95% confidence interval and percentiles. For tests of muscle strength, power, and endurance, men performed better than women (p < 0.001). For flexibility tests, women achieved greater distances than men for the sit and reach test (p < 0.001), but no difference for ankle dorsiflexion (p = 0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, men presented higher values for lower limb strength and power, as well as trunk endurance than women, whereas women demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective because the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.

Feedback Leads to Better Exercise Quality in Adolescents with Patellofemoral Pain.

Adolescents with patellofemoral pain (PFP) do not comply with their exercise prescription, performing too few and too fast repetitions, compromising recovery. We investigated if real-time feedback on contraction time would improve the ability of adolescents with PFP to perform exercises as prescribed. A randomized, controlled, participant-blinded, superiority trial with a 6-wk intervention of three weekly sessions of three elastic band exercises was undertaken. Forty 15- to 19-yr-old adolescents with PFP were randomized to real-time BandCizer™-iPad feedback on contraction time or not by a physiotherapist. The primary outcome was the mean deviation from the prescribed contraction time of 8 s per repetition. Secondary outcomes included isometric hip and knee strength, Kujala Patellofemoral Scale, and Global Rating of Change. The mean deviation from prescribed 8 s per repetition contraction time was 1.5 ± 0.5 s for the feedback group, compared with 4.3 ± 1.0 s for the control group (mean difference: 2.7 s (95% confidence interval = 2.2-3.2, P < 0.001). On the basis of total contraction time during the intervention, the feedback group received 35.4% of the prescribed exercise dose whereas the control group received 20.3%. Isometric hip and knee strength increased significantly more in the feedback group compared with controls (mean difference = 1.35 N·kg, 95% confidence interval = 0.02-2.68, P = 0.047). There were no significant differences in Kujala Patellofemoral Scale and Global Rating of Change between groups, but the study was not powered for this. Real-time feedback on contraction time resulted in the ability to perform exercises closer to the prescribed dose and also induced larger strength gains.

The Effect of Therapeutic Exercise on Long-Standing Adductor-Related Groin Pain in Athletes: Modified Hölmich Protocol.

Objective The Hölmich protocol in therapeutic exercise is the most appropriate method for the treatment of long-standing adductor-related groin pain (LSAGP). Herein, we evaluated a modified Hölmich protocol to resolve the possible limitations intrinsic to the Hölmich protocol in terms of the rate of return to sport and the recovery period for athletes with LSAGP. Design The study followed a single-blind, before/after study design, where 15 athletes with LSAGP (mean age = 26.13 years; SD = 4.48) performed a 10-week modified Hölmich therapeutic exercise protocol. Results Outcome scores related to pain, hip adductor and abductor muscle strengths, and the ratio of maximum isometric and eccentric hip adduction to abduction strength increased significantly. Likewise, hip abduction and internal rotation ROM improved significantly compared to that at baseline. Furthermore, functional records (t-test, Edgren Side Step Test, and Triple Hop Test) showed significant improvement after treatment. Finally, 13 athletes (86.6% of the participants) successfully returned to sports activity in a mean time of 12.06 weeks (SD = 3.41). Conclusion The findings of this study objectively show that the modified Hölmich protocol may be safer and more effective than the Hölmich protocol in athletes with LSAGP in promoting their return to sports activity. This trial is registered with IRCT2016080829269N1.