Effects of repetitive baseball throwing on hip muscle strength and trunk and pelvic motions at the shoulder's maximum external rotation position during the late cocking phase and ball release

[Purpose] This study aimed to investigate the changes in the trunk and pelvic lateral tilt angles at the shoulder's maximum external rotation during the late cocking phase (MER) and ball release (BR) and hip muscle strength during repetitive throwing. [Participants and Methods] In this study, 12 male baseball players participated. During the throwing, which was filmed using a high-speed video camera, the trunk and pelvic lateral tilt angles toward the nonthrowing side were measured at the MER and BR. Hip muscle strength during abduction, adduction, and external internal rotations were measured on the throwing and nonthrowing sides. Repetitive throwing was performed for nine innings, with 15 pitches per inning. Throwing motion was compared during innings 1, 7, 8, and 9. Hip muscle strength was measured before and after repetitive throwing. [Results] Compared with the trunk lateral tilt angle toward the nonthrowing side at BR in inning 1, the angle in innings 8 and 9 increased. The strength of hip abduction, adduction, and external and internal rotations on the throwing and nonthrowing sides decreased after repetitive throwing. [Conclusion] Hip muscle strength decreases after 135 pitches, and throwing >120 pitches changes the trunk lateral tilt angle at BR.

Do femoral version abnormalities play a role in hip function of patients with hip pain?

BACKGROUND

A high prevalence of femoral version abnormalities has been observed in hip pain patients, with impact on hip range of motion and muscle strength that should be elucidated.

METHODS

Cross-sectional study. Thirty-one patients with hip pain (16 men and 15 female) were subjected to Biplanar X-Rays to quantify femoral version using three-dimensional measurements. The 62 hips were divided into normal version (10-20°, n = 18), anteverted (>20°, n = 19), and retroverted (<10°, n = 25). Joint range of motion for flexion, internal rotation, and external rotation was assessed through digital goniometry. Maximal isometric hip strength (flexion, extension, internal rotation, external rotation at 0° and 30°, abduction, adduction) was evaluated through hand-held dynamometry. Hip rotation index was calculated as external rotation minus internal rotation.

FINDINGS

Anteverted hips had greater internal rotation, while retroverted hips had greater external rotation (p = 0.001). Anteverted hips were weaker than retroverted hips for external rotation at 30° (p < 0.001), abduction (p = 0.006) and adduction (p < 0.001), and weaker than normal version hips for extension (p = 0.018). All three groups had different rotation index: retroverted>normal>anteverted (p < 0.001). The ordinal logistic regression found higher values of rotation index with higher probability of being retroverted (common odds ratio = 1.20). There was a strong correlation between femoral version group and rotation index (r_S = 0.76, p < 0.001). There was probability >70% of a hip being anteverted if the rotation index was <11°, and being retroverted if the index was >40°.

INTERPRETATION

Range of motion and muscle strength differed in hips with different femoral versions. The hip rotation index was a strong femoral version predictor.

Quantifying balance deficit in people with ankle fracture six months after surgical intervention through the Y-Balance test

BACKGROUND

Ankle fractures are among the most common traumatic fractures and have a great socio-economic impact. Consequences of an ankle fracture requiring surgical treatment (e.g. pain, reduced ankle range of motion (ROM), muscle weakness, etc.) lead to balance deterioration, which has a profound impact on activities of daily living. However, to the best of the authors' knowledge, no reliable clinical tests are available to monitor balance in patients after ankle surgery.

OBJECTIVES

To quantify single-leg dynamic balance in patients with bimalleolar ankle fracture through the Y-Balance test (YBT). The second objective was to analyze the impact of ankle dorsiflexion ROM and hip strength on balance to optimize balance rehabilitation programs.

DESIGN

Cross-sectional study.

METHODS

22 participants, who had undergone surgery after bimalleolar ankle fractures, were assessed for ankle ROM, hip strength, and dynamic balance six-months after the surgical intervention. The within-session reliability of YBT was calculated through the intraclass correlation coefficient (ICC) and the standard error of measurement (SEM). Student's t-tests were used to assess leg differences. A multiple regression analysis was performed to evaluate the role of ankle dorsiflexion ROM and hip abductor and adductor strength in predicting balance performance.

RESULTS

YBT showed high-to-excellent within-session relative reliability (Healthy leg: 0.85 ≤ ICC≤0.96; Operated leg: 0.84 ≤ ICC≤0.96). SEM values were below 3.3 %. The operated leg showed significant lower YBT scores for anterior reach direction (-9.0 %; g=-0.70) and composite score (-4.5 %; g=-0.34). Multiple regression analysis showed that both, ankle dorsiflexion and hip abductor and adductor strength explained 66 % of the variance in the YBT anterior direction of the operated leg.

CONCLUSIONS

The YBT is a reliable tool that allows the quantification of single-leg dynamic balance impairments from 6-months after surgery in patients with bimalleolar ankle fracture. Between-leg YBT differences in the anterior direction can be used as reference scores (3.3 %) for balance restoration. Balance rehabilitation programs should focus on improving ankle functionality and reducing hip muscle weakness with specific hip strength exercises and balance exercises with similar demands to the reaching tasks of the YBT to promote a faster recovery.

Hip and knee muscle torque is not impaired in the first three months of a first-time lateral ankle sprain

OBJECTIVES

The primary objective was to compare hip and knee isometric muscle strength between individuals with a first-time acute lateral ankle sprain and controls. A secondary objective was to investigate hip and knee isometric muscle strength three months post-injury.

DESIGN

Cross-sectional and prospective follow-up components.

SETTING

Laboratory environment.

PARTICIPANTS

Forty-two participants (21 acute lateral ankle sprain and 21 controls) matched for age, sex, physical activity and leg dominance participated.

MAIN OUTCOME MEASURES

Hip and knee isometric muscle torque was assessed using a rigidly fixated hand-held dynamometer. Testing in acute lateral ankle sprain participants was performed within four weeks of injury and three months post-injury. Controls were tested at one timepoint.

RESULTS

There were no differences in hip or knee isometric muscle torque between acute lateral ankle sprain and control participants (mean differences <0.08). Hip and knee isometric muscle torque in acute ankle sprain participants did not differ between baseline and three months post-injury testing (mean difference <0.06).

CONCLUSIONS

Proximal lower limb isometric strength is not impaired within the first three months of sustaining a first-time lateral ankle sprain injury. This implies that hip and knee isometric strength deficits in individuals with CAI may occur at some later stage.

Hip and groin function and strength in male ice hockey players with and without hip and groin problems in the previous season- a prospective cohort study

OBJECTIVE

To describe and compare hip and groin strength and function of male ice hockey players over one season in players with and without hip and groin problems in the previous season.

DESIGN

Prospective cohort study.

SETTING

Swedish male ice hockey.

PARTICIPANTS

We followed 193 players from 10 teams during the 2017/2018 season.

MAIN OUTCOME MEASURES

Hip adduction and abduction strength, 5 s squeeze test (5SST), and self-reported hip and groin function (Hip and Groin Outcome Score). Changes over the season and differences between players with and without problems in the previous season were analyzed by linear mixed models.

RESULTS

Adduction strength decreased slightly from pre-to mid-season and abduction strength increased slightly over the full season. However, self-reported function or pain did not change. Players with hip and groin problems in the previous season had significantly worse self-reported function, and more groin pain during the 5SST compared to players without. Strength measurments did not differ between groups.

CONCLUSIONS

Hip muscle strength, groin pain, and self-reported function appear to remain stable throughout the season in male ice hockey players. Remaining impairments in players with problems in the previous season suggest that function does not recover by ice hockey participation alone.

Is hip muscle strength normalised in patients with femoroacetabular impingement syndrome one year after surgery?: Results from the HAFAI cohort

OBJECTIVES

Little is known about hip function after hip arthroscopic surgery in patients with femoroacetabular impingement syndrome. Hence, the aim of the study was (1) to investigate changes in hip muscle strength from before to one year after hip arthroscopic surgery, (2) to compare patients with a reference group.

DESIGN

Cohort study with a cross-sectional comparison.

METHODS

Before and after hip arthroscopic surgery, patients underwent hip muscle strength testing of their hip flexors and extensors during concentric, isometric and eccentric contraction in an isokinetic dynamometer. Reference persons with no hip problems underwent tests at a single time point. Participants completed completed the Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaire and physical capacity (stair climbing loaded and unloaded, stepping loaded and unloaded and jumping) tests.

RESULTS

After surgery, hip flexion strength improved during all tests (6-13%, p<0.01) and concentric hip extension strength improved (4%, p=0.002). Hip flexion and extension strength was lower for patients than for reference persons (9-13%, p<0.05) one year after surgery. Higher hip extension strength after surgery was associated with better patient reported outcomes. Patients, who were unable to complete at minimum one test of physical capacity, demonstrated significantly weaker hip muscle strength. Compared with their healthy counterparts, female patients were more impaired than male patients.

CONCLUSIONS

One year after surgery, patients improved their maximal hip muscle strength. When compared to reference persons, maximal hip muscle strength was still impaired.

Early clinical evaluation of total hip arthroplasty by three-dimensional gait analysis and muscle strength testing

BACKGROUND

As improvement of gait is an important reason for patients to undergo total hip arthroplasty (THA) and they generally tend to evaluate its success based on postoperative walking ability, objective functional evaluation of postoperative gait is important. However, the patient's normal gait before osteoarthritis is unknown and the changes that will occur postoperatively are unclear. We investigated the change in gait and hip joint muscle strength after THA by using a portable gait rhythmograph (PGR) and muscle strength measuring device.

PATIENT AND METHODS

The subjects were 46 women (mean age: 65.9 years) with osteoarthritis of the hip. Gait analysis and muscle strength testing were performed before THA, as well as 3 weeks and 3 months after surgery. We measured the walking speed, step length, and gait trajectory using PGR prospectively. PGR is attached to the patient's waist and records signals at a sampling rate of 100 Hz. Isometric torque of hip flexion and abduction were measured by using a hand-held dynamometer.

RESULTS

There was no improvement at 3 weeks postoperatively, but the walking speed, stride length and muscle strength were clearly showed improvement at 3 months postoperatively. The walking trajectory was not normal preoperatively, since the trajectory was not symmetrical and did not intersect in the midline or form a butterfly pattern, and abnormality of the trajectory tended to persist postoperative 3 months despite resolution of hip joint pain after surgery.

CONCLUSION

Since postoperative improvement of gait is an important consideration for patients undergoing THA, it seems relevant to evaluate changes in the gait after surgery and three-dimensional analysis with a PGR may be useful for this purpose.

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.

Effects of perioperative factors and hip geometry on hip abductor muscle strength during the first 6 months after anterolateral total hip arthroplasty

[Purpose] The importance and effect of hip joint geometry on hip abductor muscle strength are well known. In addition, other perioperative factors are also known to affect hip abductor muscle strength. This study examined the relative importance of factors affecting hip abductor muscle strength after total hip arthroplasty. [Subjects and Methods] The subjects were 97 females with osteoarthritis scheduled for primary unilateral THA. The following variables were assessed preoperatively and 2 and 6 months after surgery: isometric hip abductor strength, radiographic analysis (Crowe class, postoperative femoral offset (FO)), Frenchay Activities Index, compliance rate with home exercise, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and demographic data. Factors related to isometric hip abductor muscle strength 2 and 6 months after surgery were examined. [Results] Significant factors related to isometric hip abductor muscle strength at 2 and 6 months after surgery were, in extraction order: 1. isometric hip abductor muscle strength in the preoperative period; 2. BMI; and 3. the JHEQ mental score at 2 and 6 months after surgery. [Conclusion] Preoperative factors and postoperative mental status were related to postoperative isometric hip abductor strength. FO was not extracted as a significant factor related to postoperative isomeric hip abductor strength.

An explorative randomised controlled trial

BACKGROUND

The lateral and the posterior approach are the most commonly used procedures for total hip arthroplasty. Due to the detachment of the hip abductors, lateral approach is claimed to cause reduced hip muscle strength and altered gait pattern. However, this has not been investigated in a randomised controlled trial. The aim was to compare the efficacy of total hip arthroplasty performed by lateral or posterior approach on gait function and hip muscle strength up to 12months post-operatively. We hypothesised that posterior approach would be superior to lateral approach.

METHODS

Forty-seven patients with primary hip osteoarthritis were randomised to total hip arthroplasty with either posterior or lateral approach and evaluated pre-operatively, 3 and 12months post-operatively using 3-dimensional gait analyses as objective measures of gait function, including Gait Deviation Index, temporo-spatial parameters and range of motion. Isometric maximal hip muscle strength in abduction, flexion and extension was also tested.

FINDINGS

Post-operatively, no between-group difference in gait function was observed. However, both hip abductor and flexor muscle strength improved more in the posterior approach group: -0.20(Nm/kg)[95%CI:-0.4 to 0.0] and -0.20(Nm/kg)[95%CI:-0.4 to 0.0], respectively.

INTERPRETATION

Contrary to our first hypothesis, the overall gait function in the posterior approach group did not improve more than in the lateral approach group. However, in agreement with our second hypothesis, patients in the posterior approach group improved more in hip abductor and flexor muscle strength at 12months. Further investigation of the effect of reduced maximal hip muscle strength on functional capacity is needed. ClinicalTrials.gov. No.: NCT01616667.

The reliability of evaluation of hip muscle strength in rehabilitation robot walking training

[Purpose] The primary purpose of this study was to evaluate the intraclass correlation coefficient in obtaining the torque of the hip muscle strength during a robot-assisted rehabilitation treatment. [Subjects] Twenty-four patients (15 males, 9 females) with spinal cord injury participated in the study. [Methods] The subjects were asked to walk during robot-assisted rehabilitation, and the torque of the muscle strength which was measured at hip joint flexion angles of -15, -10, -5, 0, 5, 10, 15, 20, 25, and 30 degrees. [Results] The intraclass correlation coefficient of the torque of the hip muscle strength measured by the rehabilitation training robot was excellent. [Conclusion] Our results show that measurement of torque can be used as an objective assessment of treatment with RAT.

The Immediate Effect of Neuromuscular Joint Facilitation (NJF) Treatment on Hip Muscle Strength

[Purpose] This study investigated the change in hip muscle strength of younger persons after neuromuscular joint facilitation (NJF) treatment. [Subjects] The subjects were 45 healthy young people, who were divided into two groups: a NJF group and a proprioceptive neuromuscular facilitation (PNF) group. The NJF group consisted of 21 subjects (11 males, 10 females), and the PNF group consisted of 24 subjects (11 males, 13 females). [Methods] Participants in the NJF group received NJF treatment. We measured the maximal flexor strength and the maximal extensor strength during isokinetic movement of the hip joint before and after intervention in both groups. The angular velocities used were 60°/sec and 180°/sec. [Results] The NJF group showed significant increases in the maximal flexor strength and the maximal extensor strength after the intervention at each angular velocity. In the PNF group, the maximal flexor strength of 60°/sec and the maximal extensor strength of 180°/sec were significant increases. [Conclusion] These results suggest that there is an immediate effect of NJF intervention on hip muscle strength.