The Bar Sinister: Does Handlebar Level Damage the Pelvic Floor in Female Cyclists?

Partin S, Connell K, Schrader S, LaCombe J, Lowe B, Sweeney A, Reutman S, Wang A, Toennis C, Melman A, Mikhail M, Guess M. J Sex Med. 2012 May ; 9(5): 1367–1373. doi:10.1111/j.1743-6109.2012.02680.x.

Outline for April 2016 Pelvic PT Journal Distance Club
Sallie Rediske, PT, WCS

I.                    Injuries due to cycling.

A.      Physical Trauma.

B.      Overuse injuries.

1.       Saddle-related.

a.       Chafing, perineal folliculitis, furuncles, lymphedema.

b.      50-91% of female and male riders reported genital numbness.

c.       Saddle design and saddle pressure (SP) are associated with ED in male cyclists.

II.                  Purpose.

A.      Evaluate effects of female rider selected bicycle setup and cyclist’s attributes on SP and genital sensation (GS).

III.                Hypothesis.

A.      As handlebar height is lowered relative to saddle height, SP increases and GS decreases.

IV.                Methods.

A.      Secondary analysis of data collected in previous study.

1.       Recruitment.

2.       Enrollment: 48 premenopausal women bicyclists, > 18 years old if they road > 10 miles per week. 22 runners as control.

3.       Average 28.3 miles/d. (range: 4-100).

4.       Average # of days/week: 3.8.

5.       Average duration of ride: 2.1 hours.

6.       Average # of years of riding: 7.9 (range: 0.5-30).

7.       Study design: cross-sectional analysis with control group.

B.      Observational data collection.

1.       Self-reports cycling practices, cycling-related injuries / neuro symptoms.

2.       Classification of seats as “traditional” or “cut-out”.

3.       Participants use typical set-up.

a.       Pedal at even cadence, no resistance or cadence control.

b.      SP recorded 40-60 s and measured kPA using Novel Pliance pressure map (“used to obtain accurate measurement of load distribution on hard and soft sufaces” http://www.novel.de/novelcontent/pliance).

4.       Variables.

a.       Independent variable.

i.                     Handlebar height.

ii.                   Time in saddle.

iii.                  With or without shock absorbers.

iv.                 Saddle firmness.

v.                   “Rough sit” or not.

b.      Dependent variable.

i.                     Medoc Vibratory Sensory Analyzer.

ii.                   8 locales innervated by pudendal n.

iii.                  Clitoris, L and R perineum, anterior and posterior vagina, L and R labia, urethra.

iv.                 Participants notified researches of onset of sensation.

c.       Adjusted for age and saddle firmness.

5.       Sample size.

a.       N= 41.

b.      Median age = 33.

c.       At saddle height.

i.                     Older population (80% of older women rode at saddle height).

d.      Below saddle height.

i.                     Younger population (80% of younger women rode lower than saddle height.)

6.       Statistical analysis.

a.       Student’s t-test.

b.      Chi-squared.

c.       Fisher’s exact.

d.      Multivariable regression.

e.      All tests two-sided with significance <0 .05.="" font="">

V.                  Results.

A.      62% reported history of genital numbness, tingling, pain in past month.

B.      Mean and peak perineal SP ñ for those with handlebars below seat, but total SP not increased.

i.                     Age and saddle type adjustment.

ii.                   3.47 kPA ñ in mean perineal SP compared to those even with seat.

C.      Handlebars lower than seat associated with ñ in vibratory threshold in anterior and L labia.

D.      Anterior vaginal sensation significantly ò with lower saddle.

E.       Cut-out seat associated with independently associated with higher perineal SP.

F.       L labial GS non-significantly decreased.

G.     Areas of mid perineum most affect by handlebar height.

VI.                Discussion.

A.      Potter et al. showed ñ anterior genital pressure with drops position (females and males).

B.      Schrader et al.  showed ñ GS with use of noseless saddles in males.

C.      Carpes et al. no statistically significant association between trunk position and total SP in females.

D.      Bressel et al. looked at saddle design on pelvic angle and trunk angle in females.

i.                     Partial cut-outs increase anterior pelvic tilt regardless of tops or drops.

E.       Early study showed SP not significantly associated with GS.

i.                     GS possibly being affected by other factors than compression?

ii.                   Method of assessing pressure lacks sensitivity to detect impact?

F.       Summary of this study suggests handlebar height and saddle type may have cumulative effect on perineal SP and PF health.

VII.              Strengths and weaknesses of study.

A.      Small size. (-)

B.      Resistance and cadence not controlled. (-)

C.      Self-regulated set up. (-/+)

D.      No data about mileage in this study. Had to look back at primary study. (-)

E.       Wide ranging level of experience, hours riding per ride and years riding. (-/+)

F.       Selection bias possible. (-)

G.     More experienced cyclists, normal BMI. (-/+)

H.      No conduction of power of analysis for secondary study. (-)

I.        “Genital-focused” definition for sexual function implied in discussion. (?)