Classification of lumbopelvic-hip complex instability on kinematics amongst female team handball athletes

Motor alterations along the kinetic chain in amateur volleyball and handball athletes with shoulder pain: An observational comparative study

Overhead sports overload the shoulder complex due to movement repetition and the great amount of force created during the athletic motion, which may cause adaptations in the shoulder and lead to shoulder pain. However, overhead movements include the kinetic chain, and alterations in some of the structures throughout the kinetic chain may increase stress on the shoulder complex and be associated with shoulder pain.

PURPOSE

To compare kinetic chain components in overhead athletes with and without shoulder pain.

METHODS

Forty-one volleyball and handball athletes (21 with and 20 without shoulder pain) were included and assessed for hip internal (IR) and external rotation (ER) range of motion (ROM), hip and trunk isometric strength, trunk endurance and neuromuscular control of the lower and upper limbs (Y balance test).

RESULTS

Athletes with shoulder pain showed smaller IR ROM in both hips, lower endurance time for trunk extensors and flexors, decreased reach distance in the anterior and posteromedial direction, as well as a smaller composite score in the Y balance test (p < 0.05).

CONCLUSION

Volleyball and handball athletes with shoulder pain showed changes in ROM throughout the kinetic chain in addition to lower core endurance, and decreased neuromuscular control of lower limbs.

Standing Pelvic Tilt Is Associated With Dynamic Pelvic Tilt During Running When Measured by 3-Dimensional Motion Capture

Standing pelvic tilt (PT) is related to biomechanics linked with increased risk of injury such as dynamic knee valgus. However, there is limited evidence on how standing PT relates to dynamic PT and whether the palpation meter (PALM), a tool to measure standing PT, is valid against 3-dimensional (3D) motion analysis. The purposes of this study were to (1) determine the criterion validity of the PALM for measuring standing PT and (2) identify the relationship between standing PT and dynamic PT during running. Participants (n = 25; 10 males and 15 females) had their standing PT measured by the PALM and 3D motion analysis. Dynamic PT variables were defined at initial contact and toe off. No relationship between the 2 tools was found. Significant large positive relationships between standing PT and PT at initial contact (r = .751, N = 25, P < .001) and PT at toe off (r = .761, N = 25, P < .001) were found. Since no relationship was found between standing PT measured by the PALM and 3D motion analysis, the PALM is not a valid alternative to 3D motion analysis. Clinicians may be able to measure standing PT and gain valuable information on dynamic PT, allowing clinicians to quickly assess whether further biomechanical testing is needed.

Association of trunk and lower limb factors with shoulder complaints and sport performance in overhead athletes: A systematic review including GRADE recommendations and meta-analysis

OBJECTIVE

To identify the association of trunk and lower limb factors with shoulder complaints and sport performance in overhead athletes.

METHODS

Search performed at PubMed/Medline, Embase, CINAHL, LILACS, Cochrane, Web of Science and SPORTDiscus for observational studies. Methodological quality and strength of the evidence was assessed with the Newcastle-Ottawa Scale and GRADE. Meta-analysis and effects sizes analysis were calculated when possible.

RESULTS

Sixty-five studies were included. Low to very-low evidence suggests no association of trunk/lower limb strength, endurance, power, jump or balance with shoulder complaints and/or throwing performance. Athletes with shoulder complaints performed worse in trunk stability and endurance tests (mean difference: -6.83 (95%CI: -8.78, -4.88)). Athletes with high throwing performance presented better results in CMJ, horizontal jump, power measures and knee extension strength. For swimmers, there was no association of trunk/lower limb endurance with shoulder complaints (moderate evidence) and no association of balance and swimming performance (low evidence). Better trunk/lower limb strength, power and vertical jumps measures were associated with better swimming performance.

CONCLUSIONS

In methodologically similar studies, some trunk/lower limb outcomes are associated with shoulder complaint or sport/swimming performance. Results should be considered with caution and future studies should use better methodologies.

Effect of lumbopelvic control on landing mechanics and lower extremity muscles' activities in female professional athletes: implications for injury prevention

Background

Lumbopelvic control (LPC) has recently been associated with function, kinesiology, and load distribution on the limb. However, poor LPC has not been studied as a risk factor for lower limb injury in sports requiring frequent jump landings. The present study investigated the effects of LPC on landing mechanics and lower limb muscle activity in professional athletes engaged in sport requiring frequent landing.

Methods

This study was conducted on 34 professional female athletes aged 18.29 ± 3.29 years with the height and body mass of 173.5 ± 7.23 cm and 66.79 ± 13.37 kg, respectively. The landing error scoring system (LESS) and ImageJ software were used to assess landing mechanics. Wireless electromyography was also used to record the activity of the gluteus medius (GMed), rectus femoris, and semitendinosus. Lumbopelvic control was evaluated using the knee lift abdominal test, bent knee fall-out, active straight leg raising, and the PRONE test using a pressure biofeedback unit. Based on the LPC tests results, the participants were divided into two groups of proper LPC (n = 17) and poor LPC (n = 17).

Results

There were significant differences between the groups with proper and poor LPC in terms of the LESS test scores (P = 0.0001), lateral trunk flexion (P = 0.0001), knee abduction (P = 0.0001), knee flexion (P = 0.001), trunk flexion (P = 0.01), and GMed muscle activity (P = 0.03). There were no significant differences in the activity of the rectus femoris and semitendinosus muscles, and ankle dorsiflexion (P > 0.05).

Conclusions

Poor lumbopelvic control affects the kinematics and activity of the lower limb muscles, and may be a risk factor for lower limb injuries, especially of the knee.

Single-Leg Squat Compensations Are Associated With Softball Pitching Pathomechanics in Adolescent Softball Pitchers

Background:

A lack of lumbopelvic-hip complex (LPHC) stability is often associated with altered pitching mechanics, thus increasing pain and injury susceptibility. The single-leg squat (SLS) is a simple diagnostic tool used to examine LPHC stability.

Purpose:

To examine the relationship between trunk compensatory kinematics during the SLS and kinematics at foot contact during the windmill pitch.

Study Design:

Descriptive laboratory study.

Methods:

Participants included 55 youth and high school softball pitchers (mean age, 12.6 ± 2.2 years; height, 160.0 ± 11.0 cm; weight, 60.8 ± 15.5 kg). Kinematic data were collected at 100 Hz using an electromagnetic tracking device. Participants were asked to complete an SLS on each leg, then throw 3 fastballs at maximal effort. Values of trunk flexion, trunk lateral flexion, and trunk rotation at peak depth of the SLS were used as the dependent variables in 3 separate backward-elimination regression analyses. Independent variables examined at foot contact of the pitch were as follows: trunk flexion, trunk lateral flexion, trunk rotation, center of mass, stride length, and stride knee valgus.

Results:

The SLS trunk rotation regression (F(1,56) = 4.980, P = .030) revealed that trunk flexion predicted SLS trunk rotation (SE = 0.068, t = 2.232, P = .030) and explained approximately 7% of the variance in SLS trunk rotation (R² = 0.083, adjusted R² = 0.066). The SLS trunk flexion regression (F(1,56) = 5.755, P = 0.020) revealed that stride knee valgus significantly predicted SLS trunk flexion (SE = 0.256, t = 2.399, P = .020) and explained approximately 8% of variance in SLS trunk flexion (R² = 0.095, adjusted R² = 0.078).

Conclusion:

Additional trunk rotation and trunk flexion at peak depth of the SLS showed increased knee valgus and trunk flexion at foot contact of the pitch, both of which indicate poor LPHC stability during the softball pitch and may increase the potential for injury.

Clinical Relevance:

Players and coaches should implement SLS analyses to determine their players’ risk for injury and compensation due to poor core stability.

Sex-dependent differences in single-leg squat kinematics and their relationship to squat depth in physically active individuals

The purpose of this study is to compare recreationally physically active females and males with regard to spine, pelvis and lower limb joints peak angles in each plane of motion during a single leg squat (SLS). The second aim is to investigate the relationship between kinematics and SLS depth in females and males. Fifty-eight healthy, young adults performed 5 repetitions of a single right leg squat to maximal depth while keeping their balance. Kinematic data were obtained using an optical motion capture system. At the hip, greater adduction and greater internal rotation were observed in females than in males. Females had more extended spines and less outward bended knees throughout the SLS than did men. In males, squat depth was significantly, positively correlated with the maximal angle of the ankle (r = 0.60, p < 0.001), the knee (r = 0.87, p < 0.001), the hip (r = 0.73, p < 0.001) and the pelvis (r = 0.40, p = 0.02) in the sagittal plane. A positive significant correlation was found between SLS depth and maximal angle of the knee (r = 0.88, p < 0.001) and the ankle (r = 0.53, p = 0.01) in the sagittal plane in females. Males and females used different motor strategies at all levels of the kinematic chain during SLS.

Relationship between force-velocity-power profiles and inter-limb asymmetries obtained during unilateral vertical jumping and singe-joint isokinetic tasks

We explored the associations between force-velocity-power (FVP) profiles and inter-limb asymmetries in FVP profiles obtained during unilateral jumping and single-leg isokinetic knee extension and flexion tasks. Thirty (13 senior and 17 junior) basketball players performed unilateral jumps with different levels of unloading (0-40% body mass) and isokinetic knee extension and flexion at different angular velocities (60-300°/s) with each leg. Senior and junior basketball players exhibited similar jump performance, normalized knee extensor and flexor strength, and relatively similar jumping and isokinetic FVP profiles. No significant associations between unilateral jump and isokinetic knee extension and flexion FVP parameters were found (all r ≤ 0.26; p > 0.05). Inter-limb asymmetries had no or very weak associations with unilateral jump height (-0.2 < r < 0.2; all p > 0.1); also, inter-limb asymmetries in jump and isokinetic FVP parameters were generally weakly associated (median r < 0.1). Finally, unilateral jump height was weakly-to-moderately associated with isokinetic F₀, jumping P_max, and normalized knee extension isokinetic peak torque at 60°/s and 240°/s (r = 0.35-0.57). These results suggest that the generalizability of the FVP profile of isolated muscle groups to complex ballistic tasks is weak.

Preliminary Evaluation of Dynamic Knee Valgus and Serum Relaxin Concentrations After ACL Reconstruction

Background:

Athletes who have sustained a tear of the anterior cruciate ligament (ACL) are at a greater risk of re-tear and of developing other adverse outcomes, such as knee osteoarthritis, compared with uninjured athletes. Relaxin, a peptide hormone similar in structure to insulin, has been shown to interfere with the structural integrity of the ACL in female individuals. The purpose of the present study was to evaluate dynamic knee valgus and the serum relaxin concentration (SRC) in athletes who had previously sustained a torn ACL and in those who had not.

Methods:

The study included 22 female athletes, divided into 2 groups: those who had previously sustained a torn ACL (4 participants; torn ACL in the dominant leg in all cases) and those who had not (18 participants). Kinematic data were collected at 100 Hz. To assess dynamic knee valgus, participants performed a single-leg squat, a single-leg crossover dropdown, and a drop vertical jump at 2 time points in the menstrual cycle of the patient, pre-ovulatory and mid-luteal. SRC was determined with use of the Human Relaxin-2 Immunoassay using a blood sample obtained during the mid-luteal phase of the menstrual cycle.

Results:

Independent samples t tests were utilized to compare the differences in dynamic knee valgus and SRC between groups. For the single-leg squat, participants with a prior torn ACL were found to have significantly higher dynamic knee valgus at the mid-luteal phase but not at the pre-ovulatory phase. For the drop vertical jump and single-leg crossover dropdown, participants with a prior torn ACL were found to have significantly higher dynamic knee valgus at both the pre-ovulatory and mid-luteal phases. SRC was also significantly higher among participants with a prior torn ACL.

Conclusions:

Participants who had previously sustained a torn ACL had higher SRC and more dynamic knee valgus compared with those who had not. Further investigation of the effects of hormones as a risk factor for reinjury in participants with a prior ACL tear may be worthwhile. In addition, it may be worth monitoring hormonal and biomechanical properties in athletes during the long-term recovery from ACL reconstruction.

Level of Evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Using the single leg squat as an assessment of stride leg knee mechanics in adolescent baseball pitchers

OBJECTIVES

Lack of control of the lower extremity or trunk during single leg tasks is often associated with pathomechanic adaptations during the pitching motion which may increase the risk of pain and injury to the upper extremity. The objectives of the study were to determine the amount of variability in stride knee mechanics accounted for by compensations during a common movement assessment, the single leg squat (SLS) and to establish the usefulness of SLS as a screening tool for at-risk athletes.

DESIGN

Cross-sectional design.

METHODS

Sixty-one adolescent baseball pitchers performed a SLS on each leg. Participants performed three fastball pitches to a catcher at a regulation distance. Kinematic data were collected at 100Hz using an electromagnetic tracking device.

RESULTS

MANOVAs with follow-up one-way ANOVAs were used to examine the amount of variance in pitching knee mechanics explained by SLS compensations. At stride foot contact, there was a significant effect of SLS valgus angle on knee valgus angle (F_1,51=23.16, p<0.001, η_p²=0.31) and valgus moment (F_1,51=8.28, p=0.006, η_p²=0.14). At ball release (BR), there was a significant effect of SLS valgus angle on flexion angle (F_1,51=9.37, p=0.004, η_p²=0.16) and valgus angle (F_1,51 = 26.93, p<0.001, η_p²=0.35). Examination of the average values occurring between SFC and BR, revealed a significant effect of SLS valgus angle on knee valgus angle (F_1,51=30.91, p<0.001, η_p²=0.38).

CONCLUSIONS

SLS compensations are potentially a useful screening tool for stride knee mechanics in adolescent baseball pitchers.