Fok KL, Lee JW, Unger J, Chan K, Nozaki D, Musselman KE, Masani K. Cosine tuning determines plantarflexors’ activities during human upright standing and is affected by incomplete spinal cord injury. J Neurophysiol 123: 2343–2354, 2020. First published June 1, 2020. doi:10.1152/jn.00123.2020.
After publication of this article, errors in the Participants section and Table 1 of the materials and methods were identified by the authors. The authors provide a revised version of Table 1 and have revised the Participants section. The corrected table and Participants section are presented below. The authors apologize for these errors and state that the changes do not alter the scientific conclusions of the article in any way.
Table 1.
Summary of participant information such as age, level of impairment, and time since injury
| PBT05 | PBT08 | PBT10 | PBT13 | PBT14 | PBT16 | PBT17 | PBT18 | PBT20 | PBT22 | PBT23 | PBT24 | PBT25 | Mean (SD) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sex | F | M | F | F | F | F | F | F | F | M | F | M | F | |
| Age, yr | 32 | 60 | 43 | 57 | 59 | 55 | 38 | 54 | 56 | 88 | 38 | 51 | 53 | 52.6 (13.9) |
| Weight, kg | 49.9 | 109.2 | 47.3 | 102 | 62.3 | 47.5 | 55.6 | 83.3 | 73.7 | 77.2 | 79.9 | 81.9 | 68.9 | 72.2 (19.7) |
| Level of injury | C4 | C5 | T6 | C2 | C1 | C5 | T4 | C4 | L5 | C6 | T11 | C3 | C4 | |
| Time since injury, yr | 3.5 | 3.2 | 3.9 | 2.9 | 1.1 | 9.1 | 1.3 | 13 | 1.2 | 5.3 | 6.8 | 7.9 | 39 | 7.6 (10.1) |
| CB&M (/96) | 89 | 70 | 78 | 29 | 3 | 26 | N/A | 27 | 33 | 20 | 63 | 52 | 33 | 40.2 (27.9) |
| LE strength (/120)* | 87.5 | 115 | 104.5 | 89 | 75 | 90 | 75 | 78.5 | 70 | 81.5 | 101.5 | 97 | 89.5 | 88.8 (13.1) |
| Gait speed without aid, m/s | 1.29 | 1.28 | 1.10 | 0.72 | 0.43 | 0.88 | 0.75 | 0.91 | 0.94 | 0.83 | 1.03 | 1.29 | 0.95 | 0.954 (0.251) |
| Usual walking aid | None | None | None | Cane | 4WW | Cane | 4WW | Cane | None | None | None | Poles/4WW | Poles | |
| Mini-BESTest Score (/28) | 25 | 25 | 24 | 21 | 4 | 25 | 5 | 13 | 17 | 12 | 22 | 15 | 15 | 17.2 (7.3) |
| Fall history† | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 1 |
| AB1 | AB2 | AB3 | AB4 | AB5 | AB6 | AB7 | AB8 | AB9 | AB10 | AB11 | AB12 | AB13 | Mean (SD) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sex | F | F | F | M | F | F | M | F | F | F | F | M | F | |
| Age, yr | 54 | 57 | 47 | 67 | 59 | 53 | 57 | 84 | 62 | 56 | 55 | 51 | 40 | 57.1 (10.5) |
| Weight, kg | 61.9 | 42.3 | 55.5 | 57.4 | 49.6 | 45 | 75.4 | 43.9 | 55.7 | 44.7 | 45.3 | 69.9 | 53.6 | 53.9 (10.4) |
C, cervical; CB&M, community balance & mobility scale; LE, lower extremity; mini-BESTest, mini-Balance evaluation systems test; T, thoracic; 4WW, 4-wheeled walker.
LE strength measured with manual muscle testing of 12 muscles per LE. Maximum score per muscle is 5, resulting in a total score of 120 for 2 LE.
Retrospective falls in the previous 3 mo.
Participants
The data used in this study were previously collected in another work by Chan et al. (2019). In total, 14 young able-bodied (AB) individuals, 15 age- and sex-matched AB individuals, and 21 individuals with iSCI were in the project by Chan et al. (2019). The individuals with iSCI underwent two baseline assessments, separated by 2 wk. Here, we focus on the individuals with iSCI (iSCI-group) during their baseline 1 assessments and the age- and sex-matched AB individuals (AB-group). The age-matched individuals were ±3 yr of age from the corresponding individuals with iSCI and had no medical history of neurological disorders. Two age- and sex-matched participants were excluded from analysis due to technical issues during data collection. Additionally, at the time of data analysis motion capture data from three individuals with iSCI were not yet processed, and an additional five individuals in the iSCI-group were excluded from analysis due to technical issues related to motion capture and electromyography recordings. Therefore, in this study, 13 AB adults (10 females, age: 57.1 ± 10.5 yr), and 13 individuals with iSCI (10 females, age: 52.6 ± 13.9 yr, 7.6 ± 10.1 yr postinjury) were analyzed. The recruited individuals with iSCI were American Spinal Injury Association Impairment Scale (AIS) C or D (Marino et al. 2003), had moderate trunk control, and could stand for at least 30 s without mobility aids. The participants’ demographic data are summarized in Table 1. There was no significant difference in the age between the two groups (t test, P = 0.366). Body weight was significantly larger in participants with iSCI (t test, P = 0.008). All participants gave their written informed consent to participate in the study, whose experimental procedures were approved by the local ethics committee.
A registered physical therapist performed the lower extremity (LE) manual muscle test to evaluate motor function of the MG, SOL, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, semitendinosus, semimembranosus, iliopsoas, gluteus medius, and gluteus maximus (Kendall et al. 2005). Additionally, the mini Balance Evaluation Systems Test (mini-BESTest) (Franchignoni et al. 2010) and community balance and mobility (CB&M) (Inness et al. 2011) assessment were performed to assess balance ability. The CB&M scale is a test designed to evaluate balance and mobility in ambulatory individuals who have balance impairments which reduce their full engagement in community living. It has been found to have less of a ceiling effect when compared to the typical Berg Balance Scale, a better ability to capture change in these higher functioning individuals, and is a valid measure for individuals with iSCI (Chan et al. 2017; Inness et al. 2011). Participants are not allowed to use a walking aid during the CB&M assessment’ as a result, one participant was unable to perform the CB&M due to this restriction. Higher values indicate the higher functions.