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Resting pectoralis minor muscle length: An accurate way to determine if the muscle is shortened?
Journal of Hand Therapy 30 (2017) e9
Contents lists available at ScienceDirect
Journal of Hand Therapy journal homepage: www.jhandtherapy.org
Letter to the Editor
Resting pectoralis minor muscle length: An accurate way to determine if the muscle is shortened? To the Editor: We are writing to comment on the interesting article by Rosa et al1 entitled “Effects of a stretching protocol for the pectoralis minor muscle on muscle length, function, and scapular kinematics in individuals with and without shoulder pain.” In this study, the authors investigated the effects of a pectoralis minor muscle (PMm) stretching program on pain, function, PMm length, and scapular kinematics in participants, with or without shoulder pain, who had a shortened PMm. The authors reported an improvement in pain and function in those with shoulder pain; however, no differences were noted in PMm length or scapular kinematics in either group following the stretching program. We would like to discuss their method for determining whether the PMm was shortened. Following previously established methods,2,3 PMm length was measured with a tape measure as the distance between the coracoid process and fourth rib. Measurements were taken under 2 conditions: resting positiondstanding relaxed posture with arms resting at their side and retracted positiondparticipants actively performed scapular retraction and held this position during the measurement. Resting position measures were then used to determine the pectoralis minor index (PMi) (PMi ¼ [PMm length/height] 100), and subjects were deemed to have a shortened PMm if their PMi was below a predetermined value of 9.93. In our opinion, this approach for determining if the PMm is shortened is not appropriate. We liken the approach to that of determining hamstring shortness by measuring the distance between the ischial tuberosity and proximal tibia/fibula, when an individual stands in their natural relaxed posture. To the best of our knowledge, this is not how hamstring shortness is assessed. Tests such as the straight leg raise4 or 90-905 test, where the hamstring muscles are lengthened, are typically used to assess hamstring shortness. Recently, we published a reliability and validity article for our method of measuring PMm length when the muscle is in a lengthened position.6 Based on this length measure and the resting length measure, a PMm extensibility measure can be derived. We believe that this measure of muscle extensibility is more appropriate for determining if a PMm is shortened.
We would like to add to the author’s explanation for why there was a lack of a difference in PMm length following the stretching protocol that perhaps none of the subjects in the study had a shortened PMm to begin with. In light of this, we propose that the most appropriate next step in this line of research is to establish a PMm extensibility cut point for defining a shortened PMm.
References 1. Rosa DP, Borstad JD, Pogetti LS, Camargo PR. Effects of a stretching protocol for the pectoralis minor on muscle length, function, and scapular kinematics in individuals with and without shoulder pain. J Hand Ther. 2017;30(1):20e29. 2. Borstad JD, Ludewig PM. The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals. J Orthop Sports Phys Ther. 2005;35(4):227e238. 3. Rosa DP, Borstad JD, Pires ED, Camargo PR. Reliability of measuring pectoralis minor muscle resting length in subjects with and without signs of shoulder impingement. Braz J Phys Ther. 2016;20:176e183. 4. Kendall FP, McCreary EK, Provance PG, Rodgers MM, Romani WA. Muscles Testing and Function With Posture and Pain. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005. 5. Magee DJ. Orthopedic Physical Assessment. 5th ed. St. Louis, MO: Saunders Elsevier; 2008. 6. Finley M, Goodstadt N, Soler D, Somerville K, Friedman Z, Ebaugh D. Reliability and validity of active and passive pectoralis minor muscle length measures. Braz J Phys Ther. 2017;21:212e218.
David Ebaugh, PhD, PT* Margaret Finley, PhD, PT Noel Goodstadt, DPT, PT, OCS, CSCS Physical Therapy & Rehabilitation Sciences Department College of Nursing and Health Professions Drexel University, Philadelphia, PA, USA *Corresponding author. Physical Therapy & Rehabilitation Sciences Department College of Nursing and Health Professions Drexel University 1601 Cherry Street, MS 7-502 Philadelphia, PA 19012, USA. Tel.: þ1 267 359 5555; fax: þ1 267 359 5576. E-mail address: [email protected] (D. Ebaugh)
DOI of original article: 10.1016/j.jht.2016.06.006. 0894-1130/$ e see front matter Ó 2017 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jht.2017.06.005
Contents lists available at ScienceDirect
Journal of Hand Therapy journal homepage: www.jhandtherapy.org
Letter to the Editor
Resting pectoralis minor muscle length: An accurate way to determine if the muscle is shortened? To the Editor: We are writing to comment on the interesting article by Rosa et al1 entitled “Effects of a stretching protocol for the pectoralis minor muscle on muscle length, function, and scapular kinematics in individuals with and without shoulder pain.” In this study, the authors investigated the effects of a pectoralis minor muscle (PMm) stretching program on pain, function, PMm length, and scapular kinematics in participants, with or without shoulder pain, who had a shortened PMm. The authors reported an improvement in pain and function in those with shoulder pain; however, no differences were noted in PMm length or scapular kinematics in either group following the stretching program. We would like to discuss their method for determining whether the PMm was shortened. Following previously established methods,2,3 PMm length was measured with a tape measure as the distance between the coracoid process and fourth rib. Measurements were taken under 2 conditions: resting positiondstanding relaxed posture with arms resting at their side and retracted positiondparticipants actively performed scapular retraction and held this position during the measurement. Resting position measures were then used to determine the pectoralis minor index (PMi) (PMi ¼ [PMm length/height] 100), and subjects were deemed to have a shortened PMm if their PMi was below a predetermined value of 9.93. In our opinion, this approach for determining if the PMm is shortened is not appropriate. We liken the approach to that of determining hamstring shortness by measuring the distance between the ischial tuberosity and proximal tibia/fibula, when an individual stands in their natural relaxed posture. To the best of our knowledge, this is not how hamstring shortness is assessed. Tests such as the straight leg raise4 or 90-905 test, where the hamstring muscles are lengthened, are typically used to assess hamstring shortness. Recently, we published a reliability and validity article for our method of measuring PMm length when the muscle is in a lengthened position.6 Based on this length measure and the resting length measure, a PMm extensibility measure can be derived. We believe that this measure of muscle extensibility is more appropriate for determining if a PMm is shortened.
We would like to add to the author’s explanation for why there was a lack of a difference in PMm length following the stretching protocol that perhaps none of the subjects in the study had a shortened PMm to begin with. In light of this, we propose that the most appropriate next step in this line of research is to establish a PMm extensibility cut point for defining a shortened PMm.
References 1. Rosa DP, Borstad JD, Pogetti LS, Camargo PR. Effects of a stretching protocol for the pectoralis minor on muscle length, function, and scapular kinematics in individuals with and without shoulder pain. J Hand Ther. 2017;30(1):20e29. 2. Borstad JD, Ludewig PM. The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals. J Orthop Sports Phys Ther. 2005;35(4):227e238. 3. Rosa DP, Borstad JD, Pires ED, Camargo PR. Reliability of measuring pectoralis minor muscle resting length in subjects with and without signs of shoulder impingement. Braz J Phys Ther. 2016;20:176e183. 4. Kendall FP, McCreary EK, Provance PG, Rodgers MM, Romani WA. Muscles Testing and Function With Posture and Pain. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005. 5. Magee DJ. Orthopedic Physical Assessment. 5th ed. St. Louis, MO: Saunders Elsevier; 2008. 6. Finley M, Goodstadt N, Soler D, Somerville K, Friedman Z, Ebaugh D. Reliability and validity of active and passive pectoralis minor muscle length measures. Braz J Phys Ther. 2017;21:212e218.
David Ebaugh, PhD, PT* Margaret Finley, PhD, PT Noel Goodstadt, DPT, PT, OCS, CSCS Physical Therapy & Rehabilitation Sciences Department College of Nursing and Health Professions Drexel University, Philadelphia, PA, USA *Corresponding author. Physical Therapy & Rehabilitation Sciences Department College of Nursing and Health Professions Drexel University 1601 Cherry Street, MS 7-502 Philadelphia, PA 19012, USA. Tel.: þ1 267 359 5555; fax: þ1 267 359 5576. E-mail address: [email protected] (D. Ebaugh)
DOI of original article: 10.1016/j.jht.2016.06.006. 0894-1130/$ e see front matter Ó 2017 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jht.2017.06.005