Advertisement

Normalization alters the interpretation of hip strength in established unilateral lower limb prosthesis users

  • Andrew Sawers
    Correspondence
    Corresponding author at: Department of Kinesiology, University of Illinois at Chicago, 1919 West Taylor Street, Rm. 646, Chicago, IL 60612, United States of America.
    Affiliations
    Department of Kinesiology, University of Illinois at Chicago, Chicago, IL 60612, United States of America
    Search for articles by this author
  • Stefania Fatone
    Affiliations
    Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL 60611, United States of America

    Department of Rehabilitation Medicine, University of Washington, Seattle, WA 98195, United States of America
    Search for articles by this author

      Highlights

      • Hip strength was associated with body-mass x thigh length in lower-limb amputees.
      • Adjusting hip strength for body-mass x thigh length revealed novel strength patterns.
      • Failure to normalize hip strength in amputees may influence treatment decisions.

      Abstract

      Background

      Valid comparisons of muscle strength between individuals or legs that differ in size requires normalization, often by simple anthropometric variables. Few studies of muscle strength in lower-limb prosthesis users have normalized strength data by any anthropometric variable, potentially confounding our understanding of strength deficits in lower-limb prosthesis users. The objective of this pilot study was to determine the need for as well as effectiveness and impact of normalizing hip strength in lower-limb prosthesis users.

      Methods

      Peak isometric hip extension and abduction torques were collected from 28 lower-limb prosthesis users. Allometric scaling was used to determine if hip torque values were significantly associated with, and therefore needed to be adjusted for, body mass, thigh length, or body mass x thigh length, and whether normalization was effective in reducing any associations. Between limb differences in peak hip torque, and correlations with balance ability, were inspected pre- and post-normalization.

      Findings

      Hip torques were consistently and significantly associated with body-mass x thigh length. Associations between peak hip torque and body-mass x thigh length were reduced by normalization. After normalization by body-mass x thigh length, between limb differences in hip extension torque, as well as the correlation between hip abduction torque and balance ability, changed from non-significant to significant.

      Interpretation

      In the absence of normalization, hip strength (i.e., peak torque) in lower-limb prosthesis users remains dependent on basic anthropometric variables, masking relationships between hip strength and balance ability, as well as between limb differences.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Clinical Biomechanics
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Bäcklund L.
        • Lemperg R.
        • Ottosson L.G.
        Leg muscle strength in below-knee amputees.
        Acta Orthop. Scand. 1968; 39: 107-116
        • Bazett-Jones D.M.
        • Cobb S.C.
        • Joshi M.N.
        • Cashin S.E.
        • Earl J.E.
        Normalizing hip muscle strength: establishing body-size-independent measurements.
        Arch. Phys. Med. Rehabil. 2011; 92: 76-82
        • Beaudart C.
        • Rolland Y.
        • Cruz-Jentoft A.J.
        • et al.
        Assessment of muscle function and physical performance in daily clinical practice: a position paper endorsed by the European Society for Clinical and Economic Aspects of osteoporosis, osteoarthritis and musculoskeletal diseases (ESCEO).
        Calcif. Tissue Int. 2019; 105: 1-14
        • Broekmans T.
        • Gijbels D.
        • Eijnde B.O.
        • et al.
        The relationship between upper leg muscle strength and walking capacity in persons with multiple sclerosis.
        Mult. Scler. 2013; 19: 112-119
        • Chaudhry S.
        • Jin L.
        • Meltzer D.
        Use of a self-report-generated Charlson comorbidity index for predicting mortality.
        Med. Care. 2005; 43: 607-615
        • Crozara L.F.
        • Marques N.R.
        • LaRoche D.P.
        • et al.
        Hip extension power and abduction power asymmetry as independent predictors of walking speed in individuals with unilateral lower-limb amputation.
        Gait Posture. 2019; 70: 383-388
        • Curtze C.
        • Postema K.
        • Akkermans H.W.
        • Otten B.
        • Hof A.L.
        The narrow ridge balance test: a measure for one-leg lateral balance control.
        Gait Posture. 2010; 32: 627-631
        • Drouin J.M.
        • Valovich-McLeod T.C.
        • Shultz S.J.
        • Gansneder B.M.
        • Perrin D.H.
        Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements.
        Eur. J. Appl. Physiol. 2004; 91: 22-29
        • Ehde D.M.
        • Czerniecki J.M.
        • Smith D.G.
        • et al.
        Chronic phantom sensations, phantom pain, residual limb pain, and other regional pain after lower limb amputation.
        Arch. Phys. Med. Rehabil. 2000; 81: 1039-1044
        • Folland J.P.
        • Mc Cauley T.M.
        • Williams A.G.
        Allometric scaling of strength measurements to body size.
        Eur. J. Appl. Physiol. 2008; 102: 739-745
        • Hafner B.J.
        • Morgan S.J.
        • Askew R.L.
        • Salem R.
        Psychometric evaluation of self-report outcome measures for prosthetic applications.
        J. Rehabil. Res. Dev. 2016; 53: 797-812
        • Hafner B.J.
        • Gaunaurd I.A.
        • Morgan S.J.
        • Amtmann D.
        • Salem R.
        • Gailey R.S.
        Construct validity of the prosthetic limb users survey of mobility (PLUS-M) in adults with lower limb amputation.
        Arch. Phys. Med. Rehabil. 2017; 98: 277-285
        • Heitzmann D.W.W.
        • Leboucher J.
        • Block J.
        • et al.
        The influence of hip muscle strength on gait in individuals with a unilateral transfemoral amputation.
        PLoS One. 2020; 15e0238093
        • Hewson A.
        • Dent S.
        • Sawers A.
        Strength deficits in lower limb prosthesis users: a scoping review.
        Prosthetics Orthot. Int. 2020; 44: 323-340
        • Hurd W.J.
        • Morrey B.F.
        • Kaufman K.R.
        The effects of anthropometric scaling parameters on normalized muscle strength in uninjured baseball pitchers.
        J. Sport Rehabil. 2011; 20: 311-320
        • James U.
        Maximal isometric muscle strength in healthy active male unilateral above-knee amputees, with special regard to the hip joint.
        Scand. J. Rehabil. Med. 1973; 5: 55-66
        • Jaric S.
        Muscle strength testing: use of normalisation for body size.
        Sports Med. 2002; 32: 615-631
        • Jaric S.
        Role of body size in the relation between muscle strength and movement performance.
        Exerc. Sport Sci. Rev. 2003; 31: 8-12
        • Jaric S.
        • Mirkov D.
        • Markovic G.
        Normalizing physical performance tests for body size: a proposal for standardization.
        J. Strength Cond Res. 2005; 19: 467-474
        • Jørgensen M.
        • Dalgas U.
        • Wens I.
        • Hvid L.G.
        Muscle strength and power in persons with multiple sclerosis - a systematic review and meta-analysis.
        J. Neurol. Sci. 2017; 376: 225-241
        • Kleiber M.
        Physiological meaning of regression equations.
        J. Appl. Physiol. (1985). 1950; 2: 417-423
        • Kowal M.
        • Rutkowska-Kucharska A.
        Muscle torque of the hip joint flexors and extensors in physically active and inactive amputees.
        Biomed. Hum. 2014; 6: 63-68
        • Kristensen O.H.
        • Stenager E.
        • Dalgas U.
        Muscle strength and poststroke hemiplegia: a systematic review of muscle strength assessment and muscle strength impairment.
        Arch. Phys. Med. Rehabil. 2017; 98: 368-380
        • Leys C.
        • Ley C.
        • Klein O.
        • Bernard P.
        • Licata L.
        Detecting outliers: do not use standard deviation around the mean, use absolute deviation around the median.
        J. Exp. Soc. Psychol. 2013; 49: 764-766
        • Lienhard K.
        • Lauermann S.P.
        • Schneider D.
        • Item-Glatthorn J.F.
        • Casartelli N.C.
        • Maffiuletti N.A.
        Validity and reliability of isometric, isokinetic and isoinertial modalities for the assessment of quadriceps muscle strength in patients with total knee arthroplasty.
        J. Electromyogr. Kinesiol. 2013; 23: 1283-1288
        • Lloyd C.H.
        • Stanhope S.J.
        • Davis I.S.
        • Royer T.D.
        Strength asymmetry and osteoarthritis risk factors in unilateral trans-tibial, amputee gait.
        Gait Posture. 2010; 32: 296-300
        • Maughan R.J.
        • Watson J.S.
        • Weir J.
        Strength and cross-sectional area of human skeletal muscle.
        J. Physiol. 1983; 338: 37-49
        • Meyer C.
        • Corten K.
        • Wesseling M.
        • et al.
        Test-retest reliability of innovated strength tests for hip muscles.
        PLoS One. 2013; 8e81149
        • Nadollek H.
        • Brauer S.
        • Isles R.
        Outcomes after trans-tibial amputation: the relationship between quiet stance ability, strength of hip abductor muscles and gait.
        Physiother. Res. Int. 2002; 7: 203-214
        • Nevill A.M.
        • Holder R.L.
        Identifying population differences in lung function: results from the Allied Dunbar national fitness survey.
        Ann. Hum. Biol. 1999; 26: 267-285
        • Nevill A.M.
        • Ramsbottom R.
        • Williams C.
        Scaling physiological measurements for individuals of different body size.
        Eur. J. Appl. Physiol. Occup. Physiol. 1992; 65: 110-117
        • Nevill A.M.
        • Stewart A.D.
        • Olds T.
        • Holder R.
        Are adult physiques geometrically similar? The dangers of allometric scaling using body mass power laws.
        Am. J. Phys. Anthropol. 2004; 124: 177-182
        • Nevill A.M.
        • Bate S.
        • Holder R.L.
        Modeling physiological and anthropometric variables known to vary with body size and other confounding variables.
        Am. J. Phys. Anthropol. 2005; (Suppl 41): 141-153
        • Owings T.M.
        • Pavol M.J.
        • Grabiner M.D.
        Lower extremity muscle strength does not independently predict proximal femur bone mineral density in healthy older adults.
        Bone. 2002; 30: 515-520
        • Palmento Government Benefits Administrators
        Lower limb prostheses.
        in: DMERC Medicare Advis December. 1994: 99-105
        • Pezzin L.E.
        • Dillingham T.R.
        • MacKenzie E.J.
        Rehabilitation and the long-term outcomes of persons with trauma-related amputations.
        Arch. Phys. Med. Rehabil. 2000; 81: 292-300
        • Powers C.M.
        • Boyd L.A.
        • Fontaine C.A.
        • Perry J.
        The influence of lower-extremity muscle force on gait characteristics in individuals with below-knee amputations secondary to vascular disease.
        Phys. Ther. 1996; 76: 369-377
        • Rutkowska-Kucharska A.
        • Kowal M.
        • Winiarski S.
        Relationship between asymmetry of gait and muscle torque in patients after unilateral transfemoral amputation.
        Appl Bionics Biomech. 2018; : 1-9
        • Ryser D.K.
        • Erickson R.P.
        • Cahalan T.
        Isometric and isokinetic hip abductor strength in persons with above-knee amputations.
        Arch. Phys. Med. Rehabil. 1988; 69: 840-845
        • Sawers A.
        • Hafner B.J.
        Narrowing beam-walking is a clinically feasible approach for assessing balance ability in lower-limb prosthesis users.
        J. Rehabil. Med. 2018; 50: 457-464
        • Sawers A.
        • Hafner B.
        Validation of the narrowing beam walking test in lower limb prosthesis users.
        Arch. Phys. Med. Rehabil. 2018; 99: 1491-1498
        • Sawers A.
        • Ting L.H.
        Beam walking can detect differences in walking balance proficiency across a range of sensorimotor abilities.
        Gait Posture. 2015; 41: 619-623
        • Sawers A.
        • Allen J.L.
        • Ting L.H.
        Long-term training modifies the modular structure and organization of walking balance control.
        J. Neurophysiol. 2015; 114: 3359-3373
        • Sawers A.
        • Kim J.
        • Balkman G.
        • Hafner B.J.
        Interrater and test-retest reliability of performance-based clinical tests administered to established users of lower limb prostheses.
        Phys. Ther. 2020; 100: 1206-1216
        • Shapiro S.S.
        • Wilk M.B.
        An analysis of variance test for normality.
        Biometrika. 1965; 52: 591-611
        • Sibley A.R.
        • Strike S.
        • Moudy S.C.
        • Tillin N.A.
        The associations between asymmetries in quadriceps strength and gait in individuals with unilateral transtibial amputation.
        Gait Posture. 2021; 90: 267-273
        • Slater L.
        • Finucane S.
        • Hargrove L.J.
        Knee extensor power predicts six-minute walk test performance in people with transfemoral amputations.
        PM R. 2021; 14: 445-451
        • Vanderburgh P.M.
        • Mahar M.T.
        • Chou C.H.
        Allometric scaling of grip strength by body mass in college-age men and women.
        Res. Q. Exerc. Sport. 1995; 66: 80-84
        • Widler K.S.
        • Glatthorn J.F.
        • Bizzini M.
        • et al.
        Assessment of hip abductor muscle strength. A validity and reliability study.
        J. Bone Joint Surg. Am. 2009; 91: 2666-2672
        • Wren T.A.P.
        • Engsberg J.R.P.
        Normalizing lower-extremity strength data for children without disability using allometric scaling.
        Arch. Phys. Med. Rehabil. 2007; 88: 1446-1451
        • Wurdeman S.R.
        • Stevens P.M.
        • Campbell J.H.
        Mobility analysis of AmpuTees II: comorbidities and mobility in lower limb prosthesis users.
        Am. J. Phys. Med. Rehab. 2018; 97: 782-788
        • Ziegler-Graham K.
        • MacKenzie E.J.
        • Ephraim P.L.
        • Travison T.G.
        • Brookmeyer R.
        Estimating the prevalence of limb loss in the United States: 2005 to 2050.
        Arch. Phys. Med. Rehabil. 2008; 89: 422-429