DIFFERENCES IN HIP MUSCLE STRENGTH AND STATIC BALANCE IN PATIENTS WITH TRANSFEMORAL AMPUTATIONS CLASSIFIED AT DIFFERENT K-LEVELS: A PRELIMINARY CROSS-SECTIONAL STUDY

BACKGROUND: Following amputation, patients with lower limb amputations (LLA) are classified into different functional mobility levels (K-levels) ranging from K0 (lowest) to K4 (highest). However, K-level classification is often based on subjective criteria. Objective measures that are able to differentiate between K-levels can help to enhance the objectivity of K-level classification. OBJECTIVE(S): The goal of this preliminary cross-sectional study was to investigate whether differences in hip muscle strength and balance parameters exist among patients with transfemoral amputations (TFA) assigned to different K-levels. METHODOLOGY: Twenty-two participants with unilateral TFA were recruited for this study, with four participants assigned to K1 or K2, six assigned to K3 and twelve assigned to K4. Maximum isometric hip strength of the residual limb was assessed in hip flexion, abduction, extension, and adduction using a custom-made diagnostic device. Static balance was investigated in the bipedal stance on a force plate in eyes open (EO) and eyes closed (EC) conditions. Kruskal-Wallis tests were used to evaluate differences between K-level groups. FINDINGS: Statistical analyses revealed no significant differences in the parameters between the three K-level groups (p>0.05). Descriptive analysis showed that all hip strength parameters differed among K-level groups showing an increase in maximum hip torque from K1/2-classified participants to those classified as K4. Group differences were also present in all balance parameters. Increased sway was observed in the K1/2 group compared to the K4 group, especially for the EC condition. CONCLUSION: Although not statistically significant, the magnitude of the differences indicates a distinction between K-level groups. These results suggest that residual limb strength and balance parameters may have the potential to be used as objective measures to assist K-level assignment for patients with TFA. This potential needs to be confirmed in future studies with a larger number of participants. Layman's Abstract Patients with lower limb amputation (LLA) are classified into different mobility levels, so-called K-levels, which are ranging from K0 (lowest) to K4 (highest). K-level classification is relevant for the patients as it determines the type of prosthetic components available. However, K-level can vary greatly based on the clinician or orthopedic technician individual assessment. Objective data from physical performance tests can help to improve K-level classification. Therefore, muscle strength tests of the amputation stump as well as balance tests were performed in this study to determine whether these parameters have the potential to support K-level classification. Twenty-two participants with a thigh amputation participated in the study (four K1/2-, six K3- and twelve K4-participants). Hip muscle strength on the amputation side was assessed as well as static balance in the double leg stance with eyes open and eyes closed. Analysis of the data showed that all hip strength parameters differed between the K-level groups, with maximum strength increasing from the K1/2 group to the K4 group. Group differences were also seen in the balance parameters with greater body sway for the K1/2 group when compared to the K4 group, especially when participants had their eyes closed. These results show that muscle strength tests of the residual limb and static balance tests may serve as additional measures to improve K-level assignment for patients with LLA. This was only an initial study and further studies with a larger number of participants are required to confirm these results. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/37456/28905 How To Cite: John S, Orlowski K, Mrkor K.U, Edelmann-Nusser J, Witte K. Differences in hip muscle strength and static balance in patients with transfemoral amputations classified at different K-levels: A preliminary cross-sectional study. Canadian Prosthetics & Orthotics Journal. 2022; Volume 5, Issue 1, No.5. https://doi.org/10.33137/cpoj.v5i1.37456 Corresponding Author: Stefanie John,Department of Sports Science, Faculty of Humanities, Otto von Guericke University, Magdeburg, Germany.E-Mail: [email protected] ID: https://orcid.org/0000-0001-6722-7195

Evaluation of Hip Frontal Plane Flexibility and Strength in Male Sprinter Runners With Unilateral Patellofemoral Arthropathy: A Case-Control Study

Background and Objectives: Patellofemoral Arthropathy (PFA) is the most common knee disorder in runners and various factors can lead to the development of its symptoms. It has been proposed that frontal plane motions of the hip and knee can raise the dynamic quadriceps angle during functional tasks. The aim of this study was to evaluate frontal plane acting hip muscle flexibility and strength differences in male sprinter runners with unilateral PFA. Methods: A total of 38 male runners complaining of peripatellar pain or showing positive unilateral patellar grind test, assigned to the normal and sound legs, and 20 matched control groups were compared in this case-control study. Participants’ hip abductor and adductor muscles strength and their flexibility were evaluated through a hand-held dynamometer and 2D motion analysis tracker software. To measure the strength, participants were positioned side-lying position, performing abduction and adduction, while a dynamometer was placed on the lateral and medial femoral epicondyle. Active and passive abduction and adduction range of motion were recorded via a camera in the supine position and the film was analyzed by the software. Results: Abductor muscle strength and abduction-to-adduction ratio on the involved side were significantly lower than the uninvolved side (P=0.029, P=0.008, d=-0.388, d=-0.459), while greater adduction and lower abduction to adduction ratio were found in the control group (P<0.001, F=3.599). Also, lesser passive abduction and active adduction range of motion were found in the control group on both sides (P<0.001, F=2.792, F=8.979). Conclusion: Strength changes of the involved side compared with uninvolved side and less flexible side, but more probably inhibited and stronger adductors in the control group may suggest impaired muscular interaction based on frontal plane muscles torque/length curve function in unilateral PFA. Changes in the strength of the involved side compared to the healthy side and the adductor muscles with more flexibility and strength but more inhibited by the abductor’s muscles in the control group could indicate.

Factors Associated with Hip and Groin Pain in Elite Youth Football Players: A Cohort Study

Background Despite hip and groin pain being commonly reported in elite youth football players, little evidence on risk factors exists. Risk factors in adult football players include reduced hip adductor strength and hip adductor/abductor strength ratios, and lower Copenhagen Hip and Groin Outcome Score (HAGOS) subscale scores. It is unknown if these factors are also predictive of pain development in youth football players. Objective To identify whether preseason hip adductor and abductor strength and HAGOS subscale scores of male and female elite youth football players are associated with in-season or historical (lifetime) hip and groin pain. Methods Preseason hip adductor and abductor strength testing and the HAGOS were undertaken by 105 elite male (n = 58) and female (n = 47) football players aged 11–15 years. Medical staff documented both players’ self-reported historical and in-season hip and groin pain. Univariate and multivariate logistic regression models were undertaken with main outcome measures in-season hip and groin pain and historical hip and groin pain and independent variables of hip muscle strength, hip muscle torque and HAGOS subscale scores. Results Twenty-three players (21.9%) self-reported in-season hip and groin pain, while 19 players (18.1%) self-reported historical hip and groin pain. Pre-season hip adductor and abductor variables and HAGOS subscale scores failed to predict in-season hip and groin pain. However, a higher body mass index (odds ratio [OR] = 1.32; 95% CI 1.01, 1.73, p = .043) and being male (OR 5.71; 95% CI 1.65, 19.7) were associated with having in-season hip and groin pain (R2 = 0.211). There was also an association between historical hip and groin pain (R2 = 0.579) and both HAGOS subscale Quality of Life (odds ratio [OR] = 0.84; 95% CI 0.77, 0.91, p < .001) and mean abductor torque (OR = 11.85; 95% CI 1.52, 91.97; p = .018). Conclusion Pre-season hip adductor and abductor strength and HAGOS subscale scores did not predict subsequent in-season hip and groin pain in elite youth football players. However, pre-season higher hip abductor strength and lower HAGOS scores were retrospectively associated with historical hip and groin pain.

Effect of side-sling plank exercise on trunk and hip muscle activation in subjects with gluteus medius weakness

BACKGROUND: The effectiveness of side-sling plank (SSP) exercises on trunk and hip muscle activation in subjects with gluteus medius (Gmed) weakness is unclear. OBJECTIVE: To quantify muscle activation of the rectus abdominis (RA), external oblique (EO), erector spinae (ES), lumbar multifidus (LM), Gmed, gluteus maximus (Gmax), and tensor fasciae latae (TFL) during SSP with three different hip rotations compared to side-lying hip abduction (SHA) exercise in subjects with Gmed weakness. METHODS: Twenty-two subjects with Gmed weakness were recruited. SHA and three types of SSP exercises were performed: SSP with neutral hip (SSP-N), hip lateral rotation (SSP-L), and hip medial rotation (SSP-M). Surface electromyography was used to measure the activation of the trunk and hip muscles. RESULTS: The trunk and hip muscles activations were generally significantly higher level during three SSP than SHA. SSP-M showed significantly lower EO activation while significantly higher ES and LM activation than SSP-L. Gmed activation was significantly higher during SSP-M than during SSP-L. TFL activation was significantly lower during SSP-M than during SSP-N and SSP-L. CONCLUSIONS: SSP could be prescribed for patients who have reduced Gmed strength after injuries. Especially, SSP-M could be applied for patients who have Gmed weakness with dominant TFL.

Hip Muscle Strength Explains Only 11% of the Improvement in HAGOS With an Intersegmental Approach to Successful Rehabilitation of Athletic Groin Pain

Background: Exercise-based rehabilitation targeting intersegmental control has high success rates and fast recovery times in the management of athletic groin pain (AGP). The influence of this approach on hip strength and lower limb reactive strength and how these measures compare with uninjured athletes (CON) remain unknown. Additionally, the efficacy of this program after return to play (RTP) has not been examined. Purpose: First, to examine differences in isometric hip strength, reactive strength, and the Hip and Groin Outcome Score (HAGOS) between the AGP and CON cohorts and after rehabilitation; second, to examine the relationship between the change in HAGOS and the change in strength variables after rehabilitation; last, to track HAGOS for 6 months after RTP. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 42 athletes diagnosed with AGP and 36 matched controls completed baseline testing: isometric hip strength, lower limb reactive strength, and HAGOS. After rehabilitation, athletes with AGP were retested, and HAGOS was collected at 3 and 6 months after RTP. Results: In total, 36 athletes with AGP completed the program with an RTP time of 9.8 ± 3.0 weeks (mean ± SD). At baseline, these athletes had significantly lower isometric hip strength (abduction, adduction, flexion, extension, external rotation: d = –0.67 to −1.20), single-leg reactive strength ( d = −0.73), and HAGOS ( r = −0.74 to −0.89) as compared with the CON cohort. Hip strength ( d = −0.83 to −1.15) and reactive strength ( d = −0.30) improved with rehabilitation and were no longer significantly different between groups at RTP. HAGOS improvements were maintained or improved in athletes with AGP up to 6 months after RTP, although some subscales remained significantly lower than the CON group ( r = −0.35 to −0.51). Two linear regression features (hip abduction and external rotation) explained 11% of the variance in the HAGOS Sports and Recreation subscale. Conclusion: Athletes with AGP demonstrated isometric hip strength and reactive strength deficits that resolved after an intersegmental control rehabilitation program; however, improved hip strength explained only 11% of improvement in the Sports and Recreation subscale. HAGOS improvements after pain-free RTP were maintained at 6 months.